(Reuters) - New York Yankees rookie ace Masahiro Tanaka, who leads Major League Baseball in wins, has been put on the disabled list with tightness in his pitching elbow, the team said on Wednesday.
Tanaka had left the team, which is in Cleveland to play the Indians, to return to New York for a magnetic resonance imaging (MRI) test on his pitching arm. The team did not yet have test results, manager Joe Girardi told reporters.
Tanaka, 25, established himself as ace of the Yankees staff as he posted a 12-4 record with a 2.51 earned run average over his first 18 starts for New York and was named to next week's All-Star Game.
After an impeccable start to the season, the Japanese hurler has had a pair of lackluster outings.
The right-hander gave up 10 hits and five earned runs over 6 2/3 innings in a 5-3 loss to the Indians on Tuesday night. Tanaka also yielded four earned runs on July 3, after allowing no more than three runs in each of his first 16 starts.
"You just hope and pray that we get good news and it's something minor," outfielder Brett Gardner told reporters.
"You worry about anybody, but he's pretty special, what he's been able to do the first half of the season."
The loss of Tanaka was the latest blow to New York's starting rotation, which has lost CC Sabathia, Ivan Nova and Michael Pineda this season.
Tanaka joined the Yankees after signing a seven-year contract worth $155 million in January after a brilliant career in Japan.
Tanaka notched a 99-35 record with a 2.30 ERA in seven seasons with Rakuten in Japan's Pacific League, and he went 24-0 with a 1.27 ERA last year on the way to a Japan Series title.
The 45-44 Yankees are in third place in the American League East, four games behind the leading Baltimore Orioles going into Wednesday's game.
(Reporting by Larry Fine in New York; Editing by Frank Pingue)