(CHICAGO) – Chicago Cubs first baseman Anthony Rizzo will have his sprained right ankle immobilized in a boot for five to seven days and then will be evaluated, keeping open the possibility that he will play again this season. Rizzo had to be helped off the field Sunday after turning his ankle while fielding a sacrifice bunt. He underwent an MRI on Monday that revealed a moderate lateral right ankle sprain, according to the team. X-rays on Sunday did not reveal a fracture. Victor Caratini started at first base for the Cubs on Monday. Manager Joe Maddon said the Ian Happ, who replaced Rizzo on Sunday, will also see time there. Rizzo, who is known for charging hard on bunt attempts, broke toward the plate in the top of the third inning when Pirates pitcher Trevor Williams squared to bunt. As he neared the ball, Rizzo's foot appeared to dig into the turf and his right ankle turned. Cubs president Theo Epstein said the team will know more about its options for Rizzo once he is out of the walking boot.