During the upcoming MLB season, Don Mattingly will probably have one of those problems every manager wants to have. He will have it at the position where he starred during his 14 years playing in the Majors with the Yankees: first base.
Regarding the MLB roster, the Marlins will enter the season with two men who can be trusted to handle the first bag. Those are 30-year-olds Jesús Aguilar and Garrett Cooper. They provide above-average bats and decent defense, though Aguilar has demonstrated those abilities over a much larger sample size.
BUT—and this is a big one—Miami has its eighth-best prospect (fourth-best among position players) waiting for a second chance to show why he’s considered the first baseman of the future.