The return of Thames gives manager Craig Counsell plenty of options at first base and the outfield. Jesus Aguilar has played well at first in Thames' absence, hitting .290 with 11 homers and 37 RBIs.
The Brewers host the Chicago Cubs on Monday night in the opener of a three-game series.
Thames can also play the corner outfield positions. The Brewers also play Ryan Braun in left field and at first base, while Domingo Santana plays right. Christian Yelich can play all three outfield positions.
Woodruff is 2-0 with a 5.01 ERA in multiple stints this season in the big leagues.
The Brewers on Sunday acquired infielder Brad Miller and cash from the Tampa Bay Rays for first baseman-outfielder Ji-Man Choi. Miller was optioned to Triple-A.