Thomas (foot) served as the designated hitter and went 0-for-3 for Double-A Akron on Tuesday.
Thomas kicked off a rehab assignment with the RubberDucks on Tuesday and will continue Wednesday, when he's expected to play five innings in the outfield. He's been sidelined by plantar fasciitis since the beginning of July. The Guardians' top affiliates -- Akron and Triple-A Columbus -- both have plenty of games left in the regular season, so Thomas will have plenty of opportunity to build up plate appearances after the long layoff.