He sustained the injury a few days ago while bunting in the batting cage. An errant ball from the pitching machine came at Halladay's body, so he threw up his bat to block it.
"It was self defense," Halladay said.
The shiner hardly affected Halladay on the mound in a 7-0 victory over the Yankees, as he allowed four hits and struck out two in six scoreless innings. He has thrown 11 scoreless innings in three Grapefruit League starts.
The Yankees had runners on second and third with two outs in the fourth inning, but Halladay induced a groundout to end the frame. It was as close to regular-season drama as a pitcher and hitter get in Spring Training.
"You're obviously trying to work on things, but you still want to compete," Halladay said.