The Marlins are going with Morrison at first base after Gaby Sanchez was optioned on Saturday to Triple-A New Orleans.
A first baseman coming up through the Minor Leagues, Morrison converted to left field in 2010 because Sanchez had secured first base.
Morrison played first on Monday in the series opener with the Rockies. On Sunday at Cleveland, the 24-year-old made his first start of the year at first base.
"I was just a little anxious, a little nervous," Morrison said, assessing the switch back to the infield. "But once I caught the first one, in the heel of the glove, I was good to go. I was like, that's not really where it's supposed to go. But I made the play."
Since the start of Spring Training, Morrison took ground balls at first base.
And during the season, he also got work at the position.
"Whenever I'd get a day off, I'd go over to first base and take ground balls," he said.