Zumaya, facing live hitters for the first time this spring, exited his bullpen session after 13 pitches and walked off the field with head trainer Rick McWane.
Zumaya, who declined to speak to reporters, is scheduled to get an MRI exam on Sunday, according to Twins manager Ron Gardenhire and general manager Terry Ryan.
"As soon as we get those results, which will be either late [Sunday] or the next day, then we'll be able to go and give you further information," Ryan said. "Anytime a guy gets an MRI, there's got to be concern. But I'm not going to overreact until the results come out. Let's hope it's not something serious."
Zumaya, who threw five pitches each to Justin Morneau and Danny Valencia, felt the discomfort on his third pitch to Drew Butera. He told his teammates he was OK while coming off the field, but also clutched his elbow while walking.
"Obviously, he felt something that was discomforting, so he came off, which was the right thing," Ryan said. "We've had this happen down here before. We've had people walk off the mound because they were hurt. I'm glad he came off there. We'll get it addressed [Sunday] and see what the results of that MRI are. It would be a little less concerning if we didn't have the history with him, which he's experienced in his career."
For Zumaya, the best-case scenario would be that he broke up scar tissue in his elbow, but the worst-case scenario would be that he could need Tommy John surgery, which he's never had before.
But Zumaya has had his share of elbow injuries in the past, as he missed all of last season after undergoing elbow surgery during Spring Training. His last game in the Majors was on June 28, 2010, when he fractured his elbow while pitching for the Tigers against the Twins at Target Field.
He was on track to make his return with Detroit last year, but had to undergo follow-up surgery to replace the screw in his elbow after complaining of elbow pain last spring.
Ryan, though, indicated that this injury is unrelated to his previous elbow problems.
"He broke his arm before," Ryan said. "It's a different situation."
Zumaya been plagued by injuries since emerging with the Tigers as a rookie sensation in 2006, when he posted a 1.94 ERA with 97 strikeouts in 83 1/3 innings.
Since that rookie season, Zumaya has missed time with a finger injury that forced him to miss 96 games in 2007, a shoulder injury in 2008 that cost him 72 games and another shoulder injury in '08 that caused him to miss 41 games before undergoing shoulder surgery in '09.
He was signed by the Twins this offseason after impressing scouts during a workout in December. The Twins inked him to a one-year contract, and only have to pay $400,000 of his $850,000 deal if they decide to cut him due to injury.