A's: Luis Barrera, OF (No. 8)
Barrera has been showing off three plus tools at times this summer. He's always made a ton of contact, and his plus bat is still showing up (he's hitting well over .400.), though his tendency to get over-aggressive at times could get exposed in the big leagues. He's a slasher who will grow into average power and it's showing up in camp. He's also displayed plus speed and plus defensive ability in the outfield.
Mariners: Jarred Kelenic, OF (No. 1/MLB No. 11)
Kelenic's been hitting the ball so hard in Tacoma, they're probably hearing the contact in Seattle. His combination of tools have stood out, with his hit and power tools the loudest, though the Mariners have loved how he's run, thrown and defended. Perhaps most importantly for a youth-laden team, he's become more of a leader, one who has maximized his time in alternate camp.
Rangers: Josh Jung, 3B (No. 1/MLB No. 54)
Jung went eighth overall in the 2019 Draft because he was one of the most polished college hitters available, and he has lived up to that billing in alternative camp. With his ability to barrel balls and control the strike zone, he looks like a potential .300 hitter with 20-25 homers per season.
Braves: Shea Langeliers, C (No. 4/MLB No. 71)
Heading into the 2019 Draft, everyone talked about Langeliers' defense behind the plate, the main reason why he was the No. 2 catcher behind Adley Rutschman. The No. 9 overall pick has been as good as advertised with his catch-and-throw skills this summer and he's been swinging the bat very well, showing a solid approach and good gap-to-gap power.
Marlins: J.J. Bleday, OF (No. 2/MLB No. 27)
Bleday has shown why the Marlins drafted him fourth overall in 2019, when he led NCAA Division I with 27 homers and 192 total bases while helping Vanderbilt with the College World Series. With his combination of hitting ability, raw and usable power and athleticism, he might be able to contribute in Miami next year.
Mets: Matt Allan, RHP (No. 5)
Allan's high ceiling on the mound netted him a $2.5 million bonus as a third-round pick in 2019, and he subsequently offered a glimpse of his immense potential while reaching Class A Short Season Brooklyn in his pro debut. And while the Mets didn't add Allan to their 60-man player pool until Aug. 15, it hasn't taken the 19-year-old righty long to emerge as the most talked-about prospect at the team's alternate site.
Nationals: Cade Cavalli, RHP (No. 4)
The Nationals believe they got a first-round steal this year in Cavalli, who spent the early part of his college career playing both ways at Oklahoma before moving to the mound full-time as a junior and becoming one of the nation's top pitching prospects. He has made an indelible impression on Nats officials with the blend of physicality and stuff he's shown at the team's alternate site, where the 22-year-old right-hander's heater reportedly has been sitting 95-98 mph and his plus, power curveball at 83-84 mph looking as good as ever.
Phillies: Rafael Marchan, C (No. 8)
Marchan made a strong impression when he got the chance to play in Grapefruit League games during Spring Training, which led to an invitation to summer camp, and he continued to impress there and now at the Phillies' alternate site. He's proving to be an above-average defender with elite hands, with a grinder mentality in terms of blocking. His baseball IQ is off the charts, helping him get better at calling games. He's also shown a strong approach at the plate, with good strike zone awareness and excellent contact skills. The power is starting to come as he adds strength and his work ethic has really stood out.
Brewers: Antoine Kelly, LHP (No. 7)
Though Kelly dominated during his pro debut last summer, posting a 1.26 ERA and 41/5 K/BB over 28 2/3 innings in the Rookie-level Arizona League, Brewers officials were quick to acknowledge that the 6-foot-6 southpaw was still very raw and inexperienced in all facets of the game. That said, the organization has been pleasantly surprised with Kelly's rapid development and overall maturation in a short amount of time at the team's alternate site, noting that the hard-throwing lefty has made significant gains with throwing his changeup and learning how to effectively hold runners -- a concept that was foreign to Kelly when he entered pro ball.
Cardinals: Matt Liberatore, LHP, Cardinals (No. 3/MLB No. 57)
Acquired by the Cardinals in the offseason trade that sent Jose Martinez and Randy Arozarena to Tampa Bay, Liberatore pitched to mixed results but still opened eyes this past spring in big league camp, pitching with improved fastball velocity to go along with his usual plus curveball. The 20-year-old left-hander and former first-round pick (2018) has continued to make strides at the team's alternate site, with club officials pegging him as the most improved and exciting pitcher in camp.
Cubs: Brailyn Marquez, LHP (No. 1/MLB No. 69)
The Theo Epstein/Jed Hoyer regime has had difficulty developing impact pitching prospects, though Marquez may change that in the near future. The hardest-throwing lefty starter in the Minors (regularly 96-98 mph, peaking at 102), he also has a power breaking ball and is building on the strides he made at the end of 2019 with his changeup and control.
Pirates: Travis Swaggerty, OF (No. 6)
After a late start at the alternate site, the Pirates' top pick in the 2018 Draft has really come on in Altoona. He's been hitting pull-side home runs, which is tough for lefties in that ballpark to do. He's also been running down balls extremely well in center field while showing off impressive arm strength.
Reds: Hunter Greene, RHP (No. 2/MLB No. 51)
Greene had Tommy John surgery in early April 2019, but you wouldn't know it based on the reports of how he's throwing now. He's making great strides beyond rehabbing from the injury, showing off plus stuff once again with excellent command. In addition, he's started to tinker with a cutter which could give him another viable weapon on the mound.