NEW YORK (AP) Masahiro Tanaka has thrown 31 pitches in a bullpen session, and the New York Yankees right-hander says he thinks he can return to the rotation this season despite a strained right hamstring.

Speaking through a translator, Tanaka says he was able to throw all his pitches with force Friday and his hamstring is getting better each day - though he has not attempted any fielding drills yet.

Tanaka and manager Joe Girardi both say they must wait to see how the pitcher feels Saturday before determining when he might start again. Girardi says he would like to slot in Tanaka against Boston early next week.

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Tanaka says he still feels discomfort in his leg, but ''it's definitely moving in the right direction.''