With alternative training sites having ended, MLB Pipeline is recapping the development highlights for the prospects involved for each organization.

Top position prospect: Jeremy Pena, SS/2B (No. 4 on Astros Top 30)

Because the Astros loaded their initial 60-man list with players who could help a contender in the big leagues this summer, the only Top 30 prospects who opened the year at their alternative site in Corpus Christi, Texas, were first baseman Taylor Jones and outfielder Chas McCormick. In the last two weeks of camp, they brought several of their best position prospects to the home of their Double-A affiliate, including Pena, catcher Korey Lee (their 2019 first-round pick) and outfielder Colin Barber.

The son of former big league second baseman Geronimo Pena, Jeremy had a reputation as a slick defender with a questionable bat when Houston drafted him in the third round out of Maine in 2018. Since turning pro, he has added strength and become better at working counts and driving the ball in the air. He batted .303/.385/.440 with 20 steals between two Class A levels in his first full pro season, and the Astros had him focus on continuing to raise his offensive ceiling while he was in Corpus Christi.

"It's really just about trying to tap into the power we think Jeremy has," said Pete Putila, Astros assistant GM in charge of player development. "He's one of the more physically gifted guys in the organization. We think mechanically there's more upside in his bat and we wanted him to get more at-bats too."

Top pitching prospect: Forrest Whitley, RHP (No. 1)

The Astros used 15 rookie pitchers in 2020, but their lone Top 100 prospect wasn't among that group. Whitley impressed during Summer Camp, running his fastball up to 98 mph and showing five pitches that each can grade as at least plus at their best. But he came down with a sore arm in Corpus Christi and after Houston shut him down, there wasn't going to be enough time to build him back up quickly enough to contribute in the Majors.

Whitley still has a high ceiling but has pitched just 86 regular-season innings in the last three years. He missed time because of a 50-game drug suspension and minor oblique and lat injuries (2018), shoulder inflammation and command issues (2019) and now the coronavirus pandemic and sore arm (2020).

"Forrest was throwing hard and everything was working," Putila said. "He got back to throwing before the end of camp and got back on track. We're going to try to get him back and facing hitters by the end of instructional league."

Youngest prospect: Colin Barber, OF (No. 9)

Another late addition to the alternative site, Barber is just 19 but fit right in against older competition. In his first at-bat in Corpus Christi, he pulled a long home run over the right-field fence.

Signed for an over-slot $1 million in the fourth round of the 2019 Draft, the California high school product has just 99 pro at-bats on his résumé, so the Astros wanted to get him some extra experience before he headed to instructional league. They love his makeup -- one club official compared it to Alex Bregman's -- and he's a potential 20-20 player with perhaps enough quickness to stay in center field and the solid arm strength to handle right field.

"Colin has that 'it' factor with his work ethic and focus," Putila said. "He's definitely an exciting player. He has a good idea at the plate and his mechanics are pretty quiet. He should have a pretty good mix of both bat and power."

2020 Draft picks

Houston didn't bring any of its four 2020 draftees to Corpus Christi. Three of them are in instructional league, led by its top pick (supplemental second round), New York prep right-hander Alex Santos.

Pleasant developments

McCormick (No. 22) made Houston's roster for the first two rounds of the playoffs despite having no big league experience. He has yet to appear in a postseason game but is on hand as a potential pinch-runner or defensive replacement. The 21st-round pick in 2017 out of NCAA Division II Millersville (Pa.) impressed in alternative camp with his consistency and his ability to get the most out of his mostly average tools.

Another late-round choice from a small school made the Astros' 40-man playoff pool without having played in the Majors previously. Right-hander Shawn Dubin (No. 16), a 13th-rounder out of Georgetown (Ky.) in 2018, opened eyes in his first full pro season by recording a .547 opponent OPS and 12.3 strikeouts per nine innings, mostly in high Class A. He continued to dominate in Corpus Christi with his plus slider and 92-97 mph four-seam fastball, and he made improvements with his changeup and command.

Right-hander Brett Conine (No. 23) was a closer at Cal State Fullerton but became a starter almost immediately after signing as an 11th-round pick two years ago. His command was his strong suit coming out of college, and he has added velocity (now working at 90-96 mph with his fastball) and developed a quality changeup since turning pro. He spent his time in Corpus Christi working on refining his low-80s slider.