As the Philadelphia Phillies continue summer camp at Citizens Bank Park, plenty of questions remain that we likely won't have the answers to until the 60-game season gets underway.

What will the rotation look like, how many innings should we expect from the starting pitchers, who is actually going to be in the Phillies bullpen, who starts in centerfield, and who will be the DH are just some of the questions that need to be answered.

But who has the most to prove this season?

That's an interesting question, especially in a 60-game sprint of a season, where both the Phillies and free agents to be are trying to make decisions on their futures.  What if free agent to be has a solid 60-game season, what kind of pay day will they expect.  What if that same player gets off to a slow start and the numbers don't look so appealing when they get to the open market?

That's why Didi Gregorius has the most to prove this season according to ESPN Senior baseball writer Buster Olney, who gave one player from each team.

After coming back from Tommy John surgery in 2019, Gregorius struggled, especially defensively, so he signed a one-year deal to play for Philadelphia and former Yankees manager Joe Girardi. He's 30 years old, and at this stage in his baseball life, he needs to get onto the field and demonstrate that last season was an outlier.

Gregorius is a very good player who missed half the 2019 season while recovering from an elbow injury.  He signed a one-year, $14 million contract after an erratic season both in the field and at the plate.

In 2019, Gregorius displayed some goof power with 16 home runs and 61 RBI in 82 games for the Yankees, but hit just .238. He had a career high 27 home runs in 2018 and hit 25 home runs in 2017, which should help serve as some protection for the middle of the Phillies lineup.