Yankees shortstop Didi Gregorius undergoes successful Tommy John surgery on right elbow

New York Yankees shortstop Didi Gregorius underwent successful Tommy John surgery on his right elbow Wednesday morning. The surgery, which was performed by Dr. David Altchek at the Hospital for Special Surgery in Manhattan, went "as expected" according to a Yankees team release.

There is still no timetable for his potential return, but Yankees manager Aaron Boone was optimistic about it during his end-of-season press conference last Friday at Yankee Stadium.

"We're optimistic that he'll be back at some point during the season," Boone said. "I don't want to speculate too much on when, but it's realistic he plays the bulk of the season with us."

The Yankees aren't 100 percent sure when Gregorius suffered the injury, but it is believed to have happened in the seventh inning of Game 2 of the American league Division Series against the Red Sox, when Didi ran to left field to field a ball hit off the Green Monster by Boston's Ian Kinsler.

"Post-game that day, he was in the trainer's room," general manager Brian Cashman said in his own end-of-season briefing Friday. "Based on his dialogue and the feeling he felt on the tweak there, on that throw was where he pinpointed it."

Gregorius played the remainder of that game as well as the last two games of the ALDS, but a pair of short-hop throws to first base in Game 4 caught everyone's attention that something may have been amiss. He underwent an MRI last Thursday that revealed the full ulnar collateral ligament tear, and Cashman revealed that Didi had at least a partial tear when the Yankees acquired him in December 2014 but it was "asymptomatic" until this year's ALDS.

"That was the finishing off of something that was a sleeping giant, I guess," Cashman said. "If something's bothering him, he's wired in a way that either he just doesn't feel it, or he purposefully conceals it. He's just the type that he's not going to focus on it, and he's going to go out and do the best he possibly can."

The loss of Gregorius, who hit .268 with 27 home runs and 86 RBI this season, is a big loss for the Yankees, and also a big loss for Didi, who enters his final year of arbitration his winter. He was pegged for a $12.4 million salary, according to MLB Trade Rumors' usually reliable projection, but he now faces a winter of uncertainty ahead of a season that will be truncated in some form.

"We do expect to get him back," Cashman said. "We do expect him to return to the player that we've obviously been enjoying for quite some time."