Chamberlain is the 10th player on the Yankees' star-studded disabled list, and while general manager Brian Cashman said that the team is hopeful that Chamberlain will recover within two weeks, he added that he could not guarantee it.
"Joba is a pretty miraculous healer, more so than anybody I've seen," Cashman said. "He does get hurt, but when he does, he usually bounces back pretty quick. At the very least, we're going to take the safe route to make sure that we can put it behind us."
Chamberlain, 27, had no record and a 3.86 ERA in 10 appearances for New York this season, spanning 9 1/3 innings. He had permitted four earned runs and 10 hits, walking six and striking out seven.
Chamberlain last pitched on Saturday, when he recorded a save in a scoreless ninth inning against the Blue Jays, and felt discomfort while warming up in the bullpen on Tuesday.
Cashman said that Chamberlain was not available to pitch on Wednesday against the Astros, and tests taken on Thursday morning by team physician Dr. Christopher Ahmad confirmed the strain.
Additionally on Thursday, right-hander David Robertson was seen by Ahmad after feeling discomfort behind his left knee following his appearance in Wednesday's game.
"He's got a little bit of crankiness there behind the knee where the hamstring attaches, so he's just day to day," Cashman said. "He's not a DL situation."
The Yankees did not immediately announce a corresponding roster move to replace Chamberlain on the active roster. Cashman mentioned Minor League pitchers Mark Montgomery, Preston Claiborne and Sam Demel among their options to promote for Friday's game.
"We're talking about a lot of different guys right now," Cashman said. "We haven't decided on what we're doing yet."
Chamberlain joins Derek Jeter, Alex Rodriguez, Curtis Granderson, Mark Teixeira, Ivan Nova, Michael Pineda, Cesar Cabral, Francisco Cervelli and Kevin Youkilis on the disabled list.
Asked how many more hits the Yankees can withstand, Cashman quipped, "I guess we're going to find out."
"We're going to keep plugging along," Cashman added. "This is a tough spot for Joba to have to take a time out for the next 14 days, but it's going to give somebody else an opportunity and somebody else a chance to find a way to help us win games.
"Somebody's bad news is somebody else's good news. Whoever draws that straw, hopefully he can come in here and continue the good times."