TORONTO -- Yankees closer Mariano Rivera threw "almost 20 pitches" in a bullpen session Saturday and reported no pain in his sore left groin, meaning he might be able to return to the mound Sunday.
"I wasn't expecting to feel anything," Rivera said before the Yankees played the Blue Jays. "That's how minor everything was. I just have to make sure that it's ready."
Rivera, 1-2 with a 1.78 ERA and a major-league leading 38 saves, first began to feel sore Aug. 15 in Seattle. The 39-year-old has pitched in five games since then and has converted a personal-best 34 save opportunities in a row overall.
Rivera, who last pitched since Tuesday at Baltimore, threw in the outfield Thursday and Friday.
Manager Joe Girardi said he would consult with the training staff before deciding whether to use Rivera Sunday.
Also Saturday, the Yankees purchased the contract of right-hander Josh Towers from Triple-A Scranton-Wilkes Barre, adding him to the 40-man roster. Catcher Kevin Cash was released to make room for Towers.
Towers, who was pulled from his start Thursday after just two innings, spent one day with the Yankees in August but did not pitch before returning to the minors.
Girardi said the move was made to add depth to New York's bullpen, which has worked 10 2-3 innings the past two days.
"[Towers] can give us some distance if we need it," Girardi said. "Or, if we need an inning, he can give us an inning."
The Blue Jays also made a roster move Saturday, activating third baseman Edwin Encarnacion off the 15-day disabled list and putting into the lineup against the Yankees.
Acquired from Cincinnati on July 31, Encarnacion was placed on the DL on Aug. 21 with a sore left hamstring. He is batting .186 with one homer and three RBIs since joining Toronto.