ST. PETERSBURG, Fla. — New York Yankees ace Masahiro Tanaka will miss his scheduled start Monday at Toronto because of what manager Joe Girardi called a slight lower right forearm strain.

Girardi announced Tanaka's strain before the Yankees' game Thursday night at Tampa Bay. He said Tanaka won't throw for five days but could start again before the regular season ends a week from Sunday.

Tanaka had an MRI exam Thursday, one day after he picked up his 14th win despite allowing four homers in the third inning of a 11-5 win over the Rays.