CLEVELAND -- Allowing nine runs in the last two innings wasn't the worst thing that happened to the New York Yankees on Thursday night.
General manager Brian Cashman said in a conference call during the game that Tanaka could return in six weeks, but didn't rule out the possibility of Tommy John surgery if the right-hander doesn't respond to a rehab program.
"Certainly disappointed for our player, for our organization," Cashman said. "He's been an important piece. We have a tremendously gifted and tough player. We'll see how he responds."
"It is what it is," manager Joe Girardi said. "We're not going to have him for at least six weeks and that's the tough part, but I'm optimistic that we'll have him back."
Tanaka was placed on the 15-day disabled list Wednesday and had an MRI in New York, one day after his worst major league outing. He flew to Seattle on Thursday.
Cashman said Tanaka saw three doctors, including Yankees head physician Dr. Christopher Ahmad, and all three agreed that a six-week rehab program was the best option at this time.
"If we knew today that the best course of action was Tommy John surgery, despite the name and the amount of the investment, we would be doing Tommy John surgery," Cashman said.
Girardi, looking for any positive sign, said, "Guys have had success doing this and we'll keep our fingers crossed. That gives you reason for optimism that he's going to pitch again for us this year."
Tanaka, who is tied for the major league lead with 12 wins, allowed five runs and 10 hits -- both career highs -- over 6 2/3 innings Tuesday night in a 5-3 loss to the Indians.
The All-Star is 12-4 with a 2.51 ERA in 18 starts, but has lost three of his past four outings.
The injury is a huge blow to a battered Yankees rotation already was missing CC Sabathia, Ivan Nova and Michael Pineda to injuries. Tanaka had been a stabilizing ace in his first season since arriving from Japan.
"We've lost 80 percent of it," Girardi said. "There's really not a whole lot that you can go back and redo. You've just got to go out and find a way."
Mets ace Matt Harvey initially tried to rehab a partial tear of his ulnar collateral ligament last year before ultimately opting for Tommy John surgery.
Harvey has been sidelined all season, but his rehabilitation appears to be going well.
"When it comes time to trying to work through it, it's a personal decision. Going down and having Tommy John surgery is a personal decision in itself. Everybody is different. No one is saying that he can't rehab and be completely fine and never have an issue again. For me, personally, it was a mental thing. It was something I didn't want to continue thinking about," Harvey said Thursday night in New York.
"I would tell him to just go with what you feel. I didn't listen to anybody. I went off of my personal feelings. It's your body that you want to throw with again. If you want to go out and try not to have it, and your mind is set to that and you're 100 percent committed to that, then more power to you. If it's the other way around, then go get it done."
Derek Jeter, playing his final regular-season game in Cleveland, went 2 for 4 in the 1,000th multihit game of his career.
"You can't sit around and feel sorry for yourselves," he said. "It's unfortunate, it's not what we planned coming out of spring training, but it gives some other guys some opportunities to step up and fill some voids. It's unfortunate but what can you do? You have to move on."
Jeter was hit on the wrist by Michael Brantley's groundball RBI single in the eighth, but said he was fine.
Prior to the game, the Yankees placed Carlos Beltran on the seven-day concussion list. Beltran was hit in the face with a ball that caromed off the batting cage Wednesday and broke his nose.
The game did nothing to lift the Yankees' spirits. New York took a 3-0 lead into the seventh, but the Indians scored four times to go ahead and blew it open with a five-run eighth.
Carlos Carrasco (2-3) pitched a scoreless inning to help the Indians gain a four-game split.
Girardi initially thought the groundball could have been a double play if it hadn't deflected off Thornton's glove.
"It happens, it's a reaction," he said. "You want your pitchers to try to field balls, but that happened to be one that is the double play ball that we're looking for."
Yangervis Solarte, recalled from Triple-A Scranton/Wilkes-Barre to replace Beltran, had an RBI single in the fifth.
The Indians presented Jeter with an electric guitar before the game. The white guitar with blue Yankees pinstripes was inscribed with Jeter's No. 2 and the words, "The Captain." ... The Yankees are 5-3 on an 11-game road trip that takes them to Baltimore this weekend for three games before the All-Star break. RHP Hiroki Kuroda (6-6) faces Orioles RHP Miguel Gonzalez (4-5) on Friday night. ... Solarte played third base. ... Cleveland begins a three-game series at home against the White Sox on Friday night. RHP Corey Kluber (8-6) faces Chicago RHP Hector Noesi (3-5).
AP Sports Writer Ira Podell in New York contributed to this report.