While sliding headfirst into home with the go-ahead run in the 12th inning of the 6-5 triumph, the outfielder jammed his finger on a bat that was lying beside the plate. As a result, Mastroianni suffered damage to his left index finger and will be available only to pinch-run the rest of the season.
"The tendon in there got stretched bad, and there's also a little chip," said Twins skipper Ron Gardenhire.
Mastroianni singled and stole second base with two outs in the 12th. Alexi Casilla then pulled a grounder to the cut of the right-field grass, where Indians second baseman Jason Kipnis scooped up the baseball and fired a throw to first. Matt LaPorta had shifted toward the middle of the infield to serve as a cutoff man -- rather than cover the base -- so Casilla beat him in a race to the bag. As that transpired, Mastroianni dashed home to score.
"Him diving in headfirst into home plate with a bat there, he probably didn't see the bat," Gardenhire said. "It's a scary place to dive into anyway, and it ended up costing him a little bit here. But it was a very good baserunning play, other than the finger part."
The 27-year-old downplayed the injury after Tuesday's contest.
"I've jammed my finger before," Mastroianni said. "Sometimes when you slide, it happens."
Gardenhire didn't seem too bothered by the fact that Mastroianni likely won't be able to pick up a bat before the season concludes. After all, the New York native proved on Tuesday he can wreak havoc on the basepaths.
"I know exactly what we have in him," Gardenhire said. "I like him a lot. He's a good extra outfielder, part-time player. If you need him for a while, get him out there. I'm not afraid to put him out on the field. He brings a lot to the table."