Tanaka is hoping to avoid Tommy John surgery and said his arm felt fine throwing on flat ground in the outfield before the Yankees opened a homestand against the Tigers.
But Joe Girardi cautioned it will be awhile before anyone knows Tanaka’s fate.
“It’s way too early,” Girardi said following the session, which involved Tanaka lightly throwing 25 times from 60 feet.
Tanaka, though, admitted to being “relieved” after throwing for the first time since a small tear in his ulnar collateral ligament was discovered last month.
He last pitched on July 8 in Cleveland, then received a platelet rich plasma injection on July 14.
If the rehab program works, Tanaka could be back at the end of the month. If not, the elbow surgery would almost certainly cause him to miss all of 2015.
“I think it went well,” Tanaka said through an interpreter. “I’m ready to take the next step.”
Tanaka is expected to play catch again Tuesday with more throws and from a longer distance, according to Girardi.
The pitcher and manager agreed they couldn’t predict when he might return, although when the injury was discovered general manager Brian Cashman said late August would be the earliest Tanaka could come back.
Regardless of how Tuesday goes, Girardi knows there’s no way to really test Tanaka until he’s further along in the recovery process.
“It’s obviously a positive he didn’t feel anything [Monday], but as I said, it was a pretty light catch,” Girardi said. “I think you have to get him on the mound to really see how he’s doing.”
Girardi did admit it was a step forward — and considering how decimated the rotation has been this season, Monday was a success, as the clubhouse is filled with Yankee starters in various states of disarray.
“I look at it as a start, really,” Girardi said. “Obviously, if there was discomfort, that would be very discouraging. So it is a positive day.”
Tanaka, who had tapered off after a blazing start to his major league career after the Yankees invested $175 million in him during the offseason, admitted he was relieved.
“I think I’m ready for the next step,” said Tanaka, who was examined by team physician Chris Ahmad on Friday, “and I’m very relieved about that.”
He also insisted he wasn’t concerned about how he would make it through the session.
“I wasn’t worried,” Tanaka said. “I was more excited about being able to throw.”
While he has yet to really test the elbow, Tanaka said he didn’t feel any discomfort and Girardi is confident the right-hander won’t try to rush back.
“He knows what he needs to do,” Girardi said. “I didn’t see him come out today and try to do too much.”
Already without CC Sabathia (knee surgery) and Ivan Nova (elbow surgery) for the rest of the season, a legitimate shot at the postseason likely rides on Tanaka’s recovery.
He was 11-1 with a 1.99 ERA through his first 14 starts, but was 1-3 with a 4.25 ERA in his last three before he was shut down.