Track stars both old and new are converging at the USATF Championships in Sacramento, CA, this weekend, all with the goal of placing in the top three to secure a berth to the World Championships in London this August. Athletes will also need an IAAF world standard mark to qualify for the championships, but unlike last year, there will be time after USAs to chase the standard. To further complicate things, any 2015 World or 2016 Diamond League champion in an event will get a bye to worlds in that event as a fourth Team USA member, so long as they compete in at least one round of any event at the USATF championships -- not necessarily the event they have a bye in. Below are our previews for all the sprints.

If you're in Canada, you can watch the USATF Championships LIVE on FloTrack here!

Men's 100m

Who: Justin Gatlin*, Christian Coleman, Trayvon Bromell*, Chris Belcher, Cameron Burrell, Ronnie Baker
*Does not have the IAAF world standard
When:
Heats: Thursday, 8:35 PM ET
Semis: Friday, 8:31 PM ET
Final: Friday, 11:02 PM ET
Why: At 35 years old, Justin Gatlin has numerous shining moments and 13 global medals to his name but also two drug suspensions that have forced him on and off the pro scene since 2002. He was on a tear in 2015, breaking 9.80 five times. Gatlin's 2016 times were slightly less impressive on the Diamond League circuit (season best of 9.80), but he still remained undefeated in the 100m that year until the Olympics--less than we can say in 2017. Gatlin's three 100m races this season have not been what he wanted, with a season best of just 10.14 and his only win coming at the Seiko Golden Grand Prix in May. Gatlin is an excellent championship racer, but with the USA's new sprint talents on display, he may well be racing just to make the team on Friday rather than for the win.

The U.S. will have no trouble finding replacements, though. Tennessee's Christian Coleman is among the racers looking to supplant Gatlin as an individual medal hopeful in the short sprints. Coleman was sixth at the Olympic Trials last year, but he's only gotten better since then, coming off an NCAA record and world lead of 9.82 in the prelims of NCAAs. Who was the last person to win that double? You guessed it: Gatlin.

Rio Olympians Trayvon Bromell and Marvin Bracy would be top contenders for the final spot. However, Bracy is missing these championships due to surgery, and Bromell is making his season debut at USAs this year due to injury, deeming him a total unknown. One other duo that's hungry for that final spot is Chris Belcher and Cameron Burrell, the college sprinters who shocked the world by both running 9.93 during the NCAA prelims, but they both lack international experience. The only other sub-10 seed is Ronnie Baker, who beat Gatlin to win at the 2017 Pre Classic in a windy 9.86 (he was seventh and third in his other two DL outings this year).

Men's 200m

Who: Christian Coleman, LaShawn Merritt, Justin Gatlin*, Noah Lyles, Chris Belcher, Ameer Webb
*Does not have the IAAF world standard
When:
Heats: Saturday, 2:48 PM ET
Semis: Sunday, 3 PM ET
Final: Sunday, 5:33 PM ET
Why: This event will see lots of repeat offenders from the 100m coming back to either get redemption or make a second team, but it will also see a few 400m types stepping down in distance.

Gatlin is part of the former group, and if he just makes the 100m team by the skin of his teeth, it would be a stretch to also predict him for the 200m team (he was beaten by an 18-year-old Lyles in the Trials semis last year). Coleman is still the world No. 2 behind 400m world-record holder Wayde Van Niekerk after clocking a 19.85, and that's a good position to be in no matter who you are. If Coleman is considered the prohibitive favorite in this event as well, that leaves two spots behind, and there's a host of people who could get them:

The prime contender in the latter group is LaShawn Merritt. Many sprinters move up in distance with age, but Merritt's body seems to be taking the opposite trajectory, with three sub-19.80 clockings last year (all faster than his previous personal best) despite every single one of his 15 senior global outdoor medals coming from a race that has a "4" in it. Merritt made both the 200 and 400 teams last year, and he has a decent shot to do the same in 2017. His 200m races this season have been OK but not as spectacular as last year, with a season best of 20.27 in a second-place finish at the Shanghai DL. Ahead of Merritt to take the win in that May 13 race was a 19-year-old Noah Lyles, who hasn't raced at all since then.

There are two other 20.0 seeds who could mix it up and steal a spot, Ameer Webb and Chris Belcher. What Webb has going for him is that he made the 2016 Olympic 200m team by finishing third at the Trials last year. But he's failed to better 20.33 in his two 200s this season, and he was just fourth in Shangai, well behind both Merritt and Lyles. Belcher beat Coleman in the NCAAs semifinal, running a ridiculous 20.01 there just hours after his 9.93 100m. But his weakness is that he didn't do nearly as well in the final, placing just fifth there with a 20.66.

Men's 400m

Who: Fred Kerley, Tony McQuay, David Verburg*, Michael Norman, Kyle Clemons*, Najee Glass*, Marcus Chambers
*: Does not have the IAAF world standard
When:
Heats: Thursday, 9:46 PM ET
Semis: Friday, 10:34 PM ET
Final: Saturday, 4:31 PM ET
Why: None of the world's best have come even close to matching Fred Kerley's NCAA times this year. Kerley was out in the prelims at last year's trials, but since then he's improved rapidly, taking the 400m win at NCAA indoors, demolishing the NCAA record with a 43.7 outdoors, and anchoring his Texas A&M team to several sub-3:00 4x400m clockings. LaShawn Merritt, the defending Trials champ, will be sitting this one out on account of his bye from being the 2016 Diamond League 400 champ. With him out of the picture, Kerley has to be considered the favorite.

The race behind him will be tight. As for the other two 2016 Olympians, Gil Roberts isn't entered in the championships this year, and David Verburg has just the eighth-best seed time and hasn't broken 46 this season. Tony McQuay, the 2013 world silver medalist, ran 44.9 this season to take third at the Doha Diamond League and also took fourth at Pre. Behind him, it's anyone's guess, as there are six athletes who have all ran between 44.7 and 44.8 within the qualifying period.

One of those 44.8 seeds to watch will be Michael Norman, who is still just 19 years old. He won the 200m world junior gold last year, and it doesn't hurt to have your 400m PR be your most recent race at the NCAA final, where he finished fourth. The one American not named Kerley in front of him in that race, Michael Cherry, is just 22 and his PB also came at NCAAs, though his only international championship experience was part of the world junior 4x400m in 2014.

The other 44.7 seeds, Kyle Clemons and Najee Glass, both haven't dipped under 45 high this year, so they'll need a big comeback to make the team. Vernon Norwood, the 2015 NCAA champion, has run well this season, splitting a 44.82 in his season opener in April and taking third at the Pre Classic. Oregon's Marcus Chambers was only sixth in the NCAA final this year, but he did split a 44.92 in the prelims.

Men's 110m Hurdles

Who: Devon Allen, Aries Merritt, Aleec Harris, Jason Richardson*, David Oliver, Jeff Porter*, Ronnie Ash*
*: Does not have the IAAF world standard
When:
Heats: Saturday, 2:20 PM ET
Semis: Sunday, 4:04 PM ET
Final: Sunday, 5:53 PM ET
Why: Aries Merritt holds the de facto best PR in the field--he's the world-record holder. But ever since his kidney transplant in late 2015, he's struggled to return to his 2012 world-record shape--or so we thought. Though Merritt just missed out on the Olympic team last year, he's improved with every race, as demonstrated by his sixth-, then fourth-, and finally first-place finish at the Shanghai, Pre, and Rome Diamond League meets this year. Merritt should be going for the win at the national championships this year, not simply trying to make the team.

Oregon's Devon Allen shocked the nation by winning USAs as a 19-year-old in 2014, and he certainly carried that through to 2016 by winning the U.S. Trials and running 13.03. He hadn't lost a single outdoor hurdles final that season until placing fifth in the Olympics, but in September he suffered a knee ligament injury playing football for the Ducks. His results since then haven't been quite as good, placing third at Pre (though he did beat Merritt in that race) with a season best of 13.11. The battle between Allen and Merritt for the win will be interesting, but they should both be safe picks for the team.

That leaves one Team USA spot for the third-place finisher, the top contenders for which seem to be Aleec Harris, David Oliver, and Jason Richardson. (Jeff Porter and Ronnie Ash made the Olympic team last year, but Porter hasn't broken 13.5 in any of his nine races this year. He was last at Shanghai DL, while Ash similarly hasn't broken 13.6.) Harris split an impressive 13.18 in France this May, and though he was only sixth at Pre, he was the top American not named Allen or Merritt there. Richardson saved his best for last to get fifth with a 13.28 SB at the Olympic Trials finals last year, but like many others his times haven't been spectacular in 2017. Oliver is an accomplished veteran, having won the World Championships in 2013, but he didn't run the final at the U.S. Trials last year. He also hasn't broken 13.4 in 2017, and he finished behind Harris at Pre.

Men's 400m Hurdles

Who: Kerron Clement, Quincy Downing, Eric Futch, Byron Robinson, Bershawn Jackson, Michael Tinsley, Johnny Dutch
When:
Heats: Friday, 9:40 PM ET
Semis: Saturday, 4:55 PM ET
Final: Sunday, 4:56 PM ET
Why: Kerron Clement is the reigning Olympic gold medalist in this event, and he's proven himself to be a fantastic championship runner who should be able to pull through this year to at least make the team, if not win like he did at the Trials last year. That being said, his international results in 2017 have been worrying to say the least, as he's gone from second to fourth to last in his three DL outings this year. He'll need an improvement on his 49.40 SB to make the team.

There are a slew of 48 low-to-mid competitors vying for those last two spots (or possibly even three), including Quincy Downing, Eric Futch, and Byron Robinson. Both Downing and Futch set their PBs of 48.13 and 48.32, respectively, to win their most recent races, just a day apart on June 9 and 10. Downing was sixth at the Olympic Trials last year, and he looks to improve upon that finish considerably this year. Futch, meanwhile, is the best NCAA talent to compete in this event having won the championships last weekend with his PB. Though Robinson didn't make it out of the semis at NCAAs, his mark of 48.58 from the West preliminaries is the fourth-best seed to enter, and he has a good chance if he can figure out how to put it together in a championship setting.

Aside from those young guns, some of the stars of old in Bershawn Jackson (34), Michael Tinsley (33), and Johnny Dutch (28) will be looking to make one more team. Jackson won the 400H world title back in 2005, and he has made every single World Championship team since 2003 (though notably he missed out on the 2012 and 2016 Olympics). That's a pedigree that's hard to ignore, but it'll be a real challenge for him to make his eighth consecutive Worlds team. His win at the Shanghai DL with a 48.63 shows he's fit, but his more recent 50.28 at Stockholm was a little subpar. Tinsley has made every global outdoor team, including the Olympics, since 2012, though he's only raced twice this season with an SB of 49.28. Dutch claimed he was retiring last summer after a devastating clip on the last hurdle of the Olympic Trials cost him his shot at the team, but indications seem to say otherwise as he's raced five times in 2017 with a best of 49.00 in his most recent race. He hasn't declared for the Trials yet, but he made the 2015 World Championship team, and if he does declare he'll be a threat.