Anderson left Tuesday's game against the Cubs after his first pitch of the fourth inning, Nick Groke of the Denver Post reports. It wasn't obvious what was ailing Anderson, but he walked gingerly off the mound and right into the clubhouse in the top of the fourth. He had given up just one hit while striking out two in his first three innings. Franklin Morales replaced Anderson in the game and would likely start Sunday if Anderson is unable to take the hill.