HOUSTON -- Astros top prospect Hunter Brown, ranked No. 71 overall by MLB Pipeline, was added to the taxi squad on Tuesday, among a flurry of moves. General manager James Click said Brown will be activated on Thursday.

The club also placed Justin Verlander (right calf) on the 15-day injured list, recalled right-hander Brandon Bielak and first baseman J.J. Matijevic and optioned outfielder Jake Meyers to Triple-A Sugar Land.

A right-handed pitcher, Brown was drafted in the fifth round in 2019 and has dominated Pacific Coast League hitters all season. He has a 2.55 ERA, a 1.08 WHIP, a .186 batting average against and 134 strikeouts over 106 innings in 23 games (14 starts) for Triple-A Sugar Land. He was brought into Sunday’s game with two outs in the third and no runners on base and threw 3 1/3 hitless innings, simulating entering a game mid-inning. His other relief appearances have been in tandem starts.

The decision to add Brown to the taxi squad was made before Verlander’s early exit on Sunday. The Astros view Brown as a viable weapon out of the bullpen for October, which is why they should choose to test drive him in that role in September. Houston’s rotation, one of the best in baseball, is already six arms deep (with Verlander), so there’s not a spot for him there. But Brown’s 99-mph fastball, devastating curveball and ability to pitch multiple innings could give the Astros an added dimension in the playoffs.

When the rosters expand on Thursday, the Astros also plan to purchase the contract of No. 3 prospect Yainer Díaz, a catcher/first baseman who played in the Futures Game, a source told MLB.com. The club has not confirmed that news.

From Sept. 1 through the end of the regular season, all clubs must carry 28 players -- two more than on the current roster -- on their active roster, with a limit of 14 pitchers.

Díaz, acquired last July from the Guardians, is slashing .306/.356/.542 with 25 homers and 96 RBIs in 105 combined game between Double-A and Triple-A. A corresponding 40-man roster move will have to be made. Adding Díaz would allow the Astros to use Christian Vázquez as the designated hitter to get his bat in the lineup.