The injury occurred in Florida while Santana was pitching in extended spring training. He was struck by a line drive before stumbling in pursuit of the ball.
An MRI exam revealed a torn tendon.
“The tendon is severed, and it will in effect end his season,” said Dan Duquette, the Orioles' vice president of baseball operations. “I know the rehab is significant for these tendon injuries. We'll have to get with him and speak to him. But he won't be able to pitch for the Orioles this season.”
The 35-year-old Santana has not pitched in the majors since 2012 with the New York Mets. The left-hander missed last season after undergoing his second major shoulder surgery, then signed a minor league contract with Baltimore in March.
Santana's return appeared on course when the Orioles purchased his contract from Triple-A Norfolk on Monday and placed him on the major league disabled list.
“He was pitching well,” Duquette said. “The last time out he had his velocity and he was able to back-door his slider. I think he had eight strikeouts and no walks, so he was right on schedule. After (Friday), he was going to come up and join the major league team, and we were going to continue the rehab in (Double-A) Bowie.”
Santana broke into the majors with Minnesota in 2000. He won both his Cy Young Awards with the Twins, going 20-6 in 2004 and 19-6 in 2006.
He was traded to New York before the 2008 season and signed a $137.5 million, six-year contract. But injuries limited him to less than four full seasons on the mound with the Mets, and his record got progressively worse — 16-7, 13-9, 11-9, 6-9.
Matt Cain activated
San Francisco activated right-hander Matt Cain from the 15-day disabled list to start Friday night against the New York Mets. Cain, 1-3 with a 3.66 earned-run average this season, had been sidelined since May 22 because of a strained right hamstring.
Cleveland activated third baseman Carlos Santana from the seven-day concussion DL. . . . Boston hitting coach Greg Colbrunn is expected to stay hospitalized for at least another week after he had bleeding in the area between his brain and the thin tissues covering it. . . .
Baltimore placed right-hander Miguel Gonzalez on the 15-day DL because of a strained oblique muscle. . . . Oakland acquired left-hander Justin Marks from Kansas City for cash considerations and optioned him to triple-A Sacramento.