Morrison was held out of Sunday's lineup against the Angels due in part to a sore back, MLB.com's Greg Johns reports. Morrison's absence probably had more to do with a left-hander being on the mound for the opposition in Hector Santiago, but it was also done with the intention of giving the first baseman a full two days to rest in advance of Tuesday's series opener against the Padres. He later entered the game Sunday to pinch-hit and substitute in at first base, so it doesn't look like he'll be at risk of missing Tuesday's game.