Ellis missed the first 13 games of the season with left knee tendinitis. He went 1 for 3 while playing five innings during a rehab game Sunday at Triple-A Memphis.
Ellis signed a one-year deal with St. Louis in the offseason. The 11-year veteran is a .407 career hitter against Milwaukee.
Shortstop Pete Kozma was optioned to Triple-A on Monday night to make room for Ellis on the 25-man roster.
