CLEVELAND (AP) — Masahiro Tanaka was placed on the 15-day disabled list Wednesday, perhaps the biggest blow yet to the New York Yankees’ battered rotation.

The rookie sensation from Japan is sidelined with inflammation in his right elbow. He had an MRI in New York and then was headed to Seattle to be examined by Dr. Christopher Ahmad, the team’s head physician. Ahmad is in Seattle for a conference.

Yankees manager Joe Girardi acknowledged he’s concerned about Tanaka’s prognosis.

“You’re always worried when you have a guy go back for an elbow MRI,” he said. “It would be a big loss. Anytime you lose a starting pitcher, they’re hard to replace. And what he’s done for us, the innings and the wins and the quality of starts, it’s hard to replace.”

The Yankees, who have also lost pitchers CC Sabathia, Michael Pineda and Ivan Nova to injuries, are 46-44 and trail first-place Baltimore by three games in the AL East.

Tanaka allowed five runs and 10 hits ”“ both career highs ”“ over 6 2-3 innings in a 5-3 loss to the Indians on Tuesday night. The All-Star is 12-4 with a 2.51 ERA in 18 starts, but has lost three of his past four outings.

Tanaka began the season 11-1 with a 1.99 ERA, but hasn’t been as effective in his past four starts, going 1-3 with a 4.25 ERA.

He’s allowed eight home runs in his last five games, including two on Tuesday, a two-run shot in the sixth by Nick Swisher that put Cleveland ahead and a solo drive by Michael Brantley in the seventh.

Girardi didn’t notice any sign that something was bothering Tanaka during the game.

“There wasn’t anything that led us to believe there was anything wrong,” Girardi said. “He told the trainers that he just felt some soreness, so we felt it was best to send him back and have an MRI. It’s the first time he’s complained (of it).”