Arizona Diamondbacks first baseman Christian Walker (oblique) has begun hitting off a tee. It's not the most significant update for Walker, who has not yet made serious advancement in his hitting progression. There is no definitive timeline for Walker's return to the D-backs at the moment, as it remains fluid based on how his strained oblique improves on a daily basis. For the time being, fantasy managers can expect him back sometime in late August. The 33-year-old All-Star slugger went on the injured list while slashing .254/.338/.476 with 23 home runs, 20 doubles, and 71 RBI through 401 at-bats. While Walker recovers, veteran switch-hitter Josh Bell should continue to function as the everyday first baseman in the desert and occupy a spot in the heart of Arizona's batting order.

Cleveland Guardians starting pitching prospect Parker Messick struck out six batters in six innings on Sunday for Double-A Akron, allowing just one hit and one walk. Over his last two starts, Messick has been impeccable (11 IP, 3H, 0 ER, 2 BB, 15 K). The 23-year-old lefty has impressed all season. Through 107 1/3 innings between High-A and Double-A, he's posted a 2.93 ERA, 1.13 WHIP, and 34:134 BB/SO. Cleveland's No. 20 prospect (per MLB.com), Messick is expected to make his MLB debut next year.

Boston Red Sox utility prospect Kristian Campbell went 2-for-4 with a solo home run on Sunday for Double-A Portland. It was the third consecutive game in which Campbell left the yard. Before this streak, he hadn't homered in 28 games (126 PAs). The young prospect has clearly found his power stroke as of late; he's slashing .385/.529/.769 in August. Overall, Campbell is having a phenomenal season. Through 89 games, he's slashing .347/.455/.577 with 29 doubles, 15 homers, 57 RBI, 20 stolen bases, and 58:80 BB/SO. Currently Boston's No. 30 prospect (per MLB.com), he's expected to make his MLB debut in 2026.

San Francisco Giants second baseman Thairo Estrada (wrist) is scheduled to begin a minor-league rehab assignment with Triple-A Sacramento on Tuesday. Recovering from a sprained left wrist, Estrada is ready to get in some game action and should be back with the Giants either sometime later this week or early next week. The 28-year-old infielder has been a major disappointment in his fourth year with the Giants this season, slashing a pitiful .216/.249/.353 with nine home runs, 14 doubles, and 43 RBI over 329 at-bats. Although he makes for a weak stash overall in fantasy leagues, Estrada should return to an everyday role at the keystone for San Francisco when he's activated from the injured list.

Tampa Bay Rays infield prospect Junior Caminero went 3-for-4 with a solo home run on Sunday for Triple-A Durham. In 19 games since returning to the Bulls from injury, Caminero is slashing .304/.325/.532 with three doubles, five homers, 10 RBI, and 2:15 BB/SO. Through 59 total games in 2024, he's slashing .274/.337/.521 with 10 doubles, 16 homers, 39 RBI, and 21:52 BB/SO. Currently MLB's No. 2 prospect (per MLB.com), fantasy baseball managers are eagerly awaiting Caminero's promotion to the majors, which should come before the season's end.