WASHINGTON - The rehab clock on Masahiro Tanaka officially starts Thursday. How long that process takes isn't clear.

The Yankees announced Tuesday that the righthander, on the DL since April 29 with a right forearm strain and right wrist tendinitis, will start Thursday for Triple-A Scranton / Wilkes-Barre. He will throw three innings or 45 pitches.

"Very much looking forward to it," Tanaka said through his translator. "Good progress. Should be OK."

Rehabbing starters typically see an increase of about 15 pitches per outing so the safe bet, though Joe Girardi declined to say, would be three rehab outings for Tanaka before his return to the rotation.

"We know we have to build him back up some. He has not been out that long. So he'll go three [innings] at 45 and we'll decide what's next."Tanaka said he's been encouraged during his four bullpen sessions.

"I was able to throw all my pitches," he said. "I feel pretty satisfied about that."

advertisement | advertise on newsday

A-Rod sits

As expected, with the Yankees playing in a National League park, 39-year-old DH Alex Rodriguez did not start Tuesday niight. He did replace Chase Headley at third base in the eighth inning in a double switch.

Shreve, Harper go back

Lefthanded reliever Chasen Shreve is familiar with Nationals lefty Bryce Harper, who entered the series leading the NL in homers (14), RBIs (37) and slugging (.729), among other categories. While at the College of Southern Nevada, Shreve's catcher for a season was Harper.

Shreve, 24, said he faced Harper, 22, once, in 2011 when both were in the South Atlantic League.

Yankees videos

The result?

"Pop to short," Shreve smiled. "First pitch."

Shreve did even better last night, striking out Harper with runners on first and second to end the seventh.