Martinez, fifth in the AL in batting with a .352 average, came to bat with two outs and none on against former teammate CC Sabathia wearing a shin guard on his left ankle.
He fouled an inside pitch off his shin, just above the guard and rolled around face down as manager Eric Wedge and trainer Lonnie Soloff came out to assist him. The switch-hitter slowly got to his feet, tried to jog, but stopped after only a couple of steps.
Martinez insisted on staying in the game and fouled off the next pitch before sending a slow roller toward second baseman Robinson Cano. Martinez took a couple of steps to first base and pulled up, then walked to first base as the out was completed.
Yankees shortstop Derek Jeter patted Martinez on the back with his glove as he headed to the dugout. Martinez, who has seven homers and a team-leading 36 RBIs, walked slowly to the third base side and was helped down the steps into Cleveland's dugout.
Kelly Shoppach replaced Martinez behind the plate to start the second inning.