Yankees manager Aaron Boone said Loaisiga will not throw for at least 10 days.
"Obviously that's a tough loss for us, which hopefully is only a couple of weeks but still something we'll have to navigate,'' Boone said.
Boone told reporters he hopes the Yankees can get Loaisiga back this season.
"Hopefully this is something that's a little bit of a timeout and we get him back for the stretch drive,'' Boone said.
Loaisiga is 9-4 with a 2.25 ERA in 68 innings pitched this season, striking out 66 batters while walking just 15. He has 18 holds and five saves. His innings pitched are his most since pitching 68 ⅔ innings in 2013 in the Dominican Summer League as a minor leaguer for the San Francisco Giants.
He last pitched on Friday against the Baltimore Orioles, when he surrendered a game-tying home run to former Yankees farmhand Jorge Mateo in the seventh inning to give him his fourth blown save of the season. Mateo's home run was just the third Loaisiga has allowed this season.
Loaisiga received a cortisone shot after feeling sore Saturday and underwent an MRI, which revealed his injury.
The Yankees recalled right-hander Albert Abreu from Triple-A Scranton/Wilkes-Barre in a corresponding move.
New York is on top of the AL wild-card standings, a half-game ahead of the Boston Red Sox.
The Associated Press contributed to this report.