Philadelphia Phillies ace Zack Wheeler will miss his scheduled start on Sunday against the Oakland Athletics due to lower back tightness, giving him extended rest through the All-Star break. An MRI revealed no structural damage, and the team is confident the extra rest will help him recover. Manager Rob Thomson emphasized precaution, indicating Wheeler could return as early as July 19 against Pittsburgh or as late as July 23 in Minnesota. The Phillies, leading their division comfortably, have not named a replacement for Sunday's game but may opt for a bullpen game. Wheeler, who has been dealing with back issues for weeks, still managed an impressive 10-4 record with a 2.70 ERA this season. Despite his All-Star selection, Wheeler will not participate in the game due to his back issues.