To make room for the two pitchers on the roster, right-hander Cole De Vries was placed on the 15-day DL retroactive to March 30 with a strained right forearm, and left-hander Tyler Robertson was optioned to Triple-A Rochester after Saturday's game.
Swarzak, who was placed on the DL on March 22 with two left rib fractures stemming from a horseplay incident in late January, is expected to be used as the club's long reliever. He also had his wisdom teeth removed on Wednesday but said he's fully recovered.
"It feels very good," Swarzak said. "There were a few weeks there in Spring Training where I wasn't sure how much time I'd miss and it was scary. But now that it was only five games and I'm back I feel ready to go."
Twins manager Ron Gardenhire said he was happy to have Swarzak with the team, as the right-hander can eat up innings as a long reliever, considering he went four innings in his last Minor League outing on Tuesday.
"It's huge," Gardenhire said. "It turned out good last night because Josh [Roenicke] picked us up, but we were sitting there talking while [Vance] Worley was battling out there that we wished we had Swarzy. So this is huge having him back. He can do a lot of things for us."
Rhett Bollinger is a reporter for MLB.com. Read his blog, Bollinger Beat, and follow him on Twitter @RhettBollinger This story was not subject to the approval of Major League Baseball or its clubs.