Left-handed 23-year-old hitter Isan Diaz should be able to win a platoon spot at second base, but could end up backing up righty Jon Berti. Diaz struggled at the plate last year (.173/.259/.307 in 49 games) while Berti emerged (.273/.348/.406 in 73 games), but it makes sense to split their at-bats if Diaz shows a noticeable improvement at the plate in Spring Training. After all, he was a highly-touted prospect and seemingly has upside. It is worth mentioning that Berti led the Marlins’ everyday players in on-base percentage last year, so he’s definitely a candidate to carve out more of a role if he continues to show that ability in 2020. Expect Berti to grab most of the at-bats at second base when the Marlins are facing left-handed pitchers, especially after Diaz managed just four hits in 40 at-bats (with 14 strikeouts) against southpaws last season. However, if the youngster emerges after some offseason adjustments, he can bolster the bottom half of this lineup, which would allow Mattingly to deploy Berti off the bench, where his versatility can come into play in mid-game situations.