Paxton missed one start while on the disabled list with a stiff lower back. He threw a bullpen session consisting of 40 pitches on Saturday.
"He felt fine, threw all his pitches and got after it in his bullpen, so no hesitation about bringing him back," Servais told reporters, according to MLB.com.
Paxton, 29, is 8-4 with a 3.70 ERA in 20 starts this season. His 155 strikeouts rank fifth in the American League.