He got the callup Wednesday night because the Phillies placed Freddy Galvis on the disabled list with a strained lower back.
"I've been working hard," Martinez said of his rehab time in Clearwater, Fla. "No one wants to be down there."
Martinez likely got the call because, with Galvis on the DL, the Phillies do not have a player who can play shortstop other than Jimmy Rollins.
"It's hard," Martinez said of his time on the DL. "That's my first time I got hurt like that. It's too long. That's baseball. Now I'm ready. Ready to play."