Brian Cashman, who referred to Masahiro Tanaka as a No. 3 starter during the winter, has been surprised by how easily the right-hander has become accustomed to Major League Baseball.

The New York Yankees signed Tanaka to a $155 million deal after shelling out a $20 million posting fee.

"He's pitched like a No. 1, he's been tremendous," Cashman said. "I would have expected a transition to some degree. You always expect a transition period coming to New York, even if it's just coming from another city (in MLB). Here, he's coming from Japan, where they have a different pitching schedule and different travel."

Tanaka is 5-0 with a 2.57 ERA, 58 strikeouts and just seven walks in 2014.