Maxwell, on the disabled list since June 26 with loose bodies in his left ankle, is on a stint at Oklahoma City, going 0-for-4 while starting in center field on Sunday in New Orleans. He's 2-for-10 in three games
Maxwell, who has eight homers in only 121 at-bats for the Astros, was originally going to have surgery before doctors informed him the procedure was more invasive than previously thought and would require a two-month recovery.
Dominguez, acquired by the Astros on Wednesday from the Marlins in the Carlos Lee trade, appeared in four games and was 2-for-8. Mills said Chris Johnson would slide back to third base after playing first the past four games, which could pave the way for Brett Wallace to be called up and start at first base in the second half.
Shortstop Marwin Gonzalez (bruised right heel) has played in 11 games in his Minor League rehab stint at Oklahoma City, but the Astros are likely to keep him there closer to the 20-game maximum for rehabs.
That gives Gonzalez the opportunity to get some extended playing time at the Triple-A level, which he can't do when healthy, because he's a Rule 5 pick and has to stay on the 25-man roster or disabled list all season. He was hitting .387 (12-for-31) for the RedHawks.