I said this last offseason, and I'll say this now:
Yasiel Puig.
He's had a wrc+ of 130 vs. RHP over the course of his career. [Yes, go ahead and check his career splits.]
He's had a positive DRS in most seasons, which suggests that he's an adequate fielder.
His acquisition cost won't include squandering the dwindling supply of tradeable assets, or surrendering compensatory picks.
His salary demands aren't going to prevent adding other pieces in this offseason, at 2021's trade deadline, at next season's offseason, or 2022's trade deadline.
He's only going to be 30, which means he should have enough tread on the tire to allow Colas or Cespedes or Adolfo or other youngsters to arrive here.
He has been supported by both Abreu and Grandal; at 30 years old, he's likely to be more mature than he was as a younger man.
He has been active in his community through his charitable foundation, moreso than most players.
He's played in this division, and should now have some familiarity with the ballparks in it.
He has players in this roster with whom he has familiarity, and the manager, if he has a strength, is to keep a clubhouse together.
He likely has been humbled by being left out this season, and is highly likely to be hungry to prove himself; a contract with the proper incentives/disincentives can easily keep him in line, for those of you who are pearl-clutching pants-wetters.
I don't think he'll ever be the 5.5 fWAR stud we thought he was a few years ago. But, I think his fWAR floor is likely ~1.5 fWAR, with a ceiling of perhaps ~3fWAR. BUT, he should come at a price point that will be less than Mazara in arb, AND at a point that won't kill the budget.
As part of an overall strategy to compete in 2021 through 2024, while not squandering dwindling resources of trade assets or salary structure space, go sign him for a reasonable contract. I'm interested in having multiple opportunities to win, which means trying to add talent that may provide surplus value [i.e. a player who might outperform his contract]. I'm not interested in this club blowing their entire prospect wad, or their entire salary structure in ONE OFFSEASON, which could prevent future additions over the course of this competitive window. IOW, I don't care about "winning the offseason" by adding your wet dream in trade or FA this offseason. YMMV.