Arizona Diamondbacks right-hander Zac Gallen (hamstring) could come off the injured list to start Saturday's game against the Oakland Athletics if all goes well with his bullpen session on Thursday. Gallen has already thrown a few simulated games, and Thursday's bullpen will be his second. So if the 28-year-old gets through Thursday without any issues, he'll be an option to return to Arizona's starting rotation this weekend in an excellent matchup that fantasy managers won't be able to pass on despite the fact that Gallen hasn't thrown in a game since May 30, when he was removed after just pitches due to his hamstring injury. Without going on a minor-league rehab assignment to build his pitch count up, though, Gallen's fantasy upside in his first start back in the big leagues will be limited.

Chicago White Sox shortstop prospect Brooks Baldwin went 4-for-5 on Wednesday with a double and two round-trippers and brought in three RBI to extend his hitting streak to eight games. After spending last summer in Single and High-A, the 23-year-old opened this season by making his Double-A debut. The UNC Wilmington product has looked excellent through 65 games this summer with a stellar .345/.412/.475 slash line, six long balls, 35 RBI, 16 stolen bases, and a 28:45 BB:K ratio. Baldwin has never seen his monthly batting average dip below .300 and has only gone hitless in consecutive games once this season. Currently, MLB Pipeline ranks Baldwin as the 24th-best prospect in the White Sox system, but with how well he has performed, he has a strong chance to improve this rank throughout the summer.

Arizona Diamondbacks reliever Miguel Castro (shoulder) threw 17 pitches in an Arizona Complex League game on Tuesday and will throw again on Saturday, possibly to rehabbing catcher Gabriel Moreno (thumb), according to manager Torey Lovullo. The skipper explained that he would not be surprised to see Castro get a look at a minor-league affiliate before coming off the injured list. The 29-year-old got some run as Arizona's closer early last year and picked up a career-high seven saves when all was said and done, but he didn't last long as a ninth-inning man and didn't get off to a good start for the Snakes in his 8 2/3 relief innings before injuring his shoulder, allowing five earned runs on 12 hits while walking one and striking out six.

Arizona Diamondbacks outfielder Alek Thomas (hamstring) was scheduled to play for Triple-A Reno on Wednesday, Friday and Saturday, according to assistant general manager Mike Fitzgerald. After that, the hope is that Thomas can return to the Diamondbacks, possibly for the series opener in Los Angeles against the division-rival Dodgers on Tuesday. In two games with the Aces already, Thomas has gone 1-for-7 and he's 8-for-20 overall on his minor-league rehab assignment, including a short stint in the Arizona Complex League. The 24-year-old could be eased back into the fold initially for the D-backs, but when fully healthy, he figures to play regularly in center field against right-handed pitching. So far, Thomas has been more useful to the Snakes for his glove in his three years in the big leagues, as he's currently slashing just .230/.273/.362 with 18 homers and 13 steals in 242 games.

St. Louis Cardinals starting pitching prospect Cooper Hjerpe tallied a season-high eight punchouts across five shutout frames on Wednesday. He allowed just two hits and two free passes. Hjerpe was recently promoted to Double-A on June 12. In his first start, he tossed only two frames and allowed a season-high five runs. However, in his two recent starts at this level, he did not allow a run and held a stellar 0.30 WHIP with a 3:14 BB:K ratio. The former first-round pick from Oregon State is beginning to find his footing at Double-A and has progressed through the minor leagues fairly quickly. The 23-year-old southpaw is ranked as the sixth-best prospect in the St. Louis system on MLB.com and remains on track to meet his 2025 major league ETA.