Marisnick, a seven-year big league veteran, has never hit all that much — his career line is .227/.280/.380 — but he’s a very strong defender at all three outfield positions and can run a good bit. That makes him a decent bench option at least. To the extent the Mets rely on him to be more than a bench guy they’ll get diminishing returns, but the Astros used him a good deal more than your standard 4-5th outfielder and that worked out fine. Really, having a no-hit, plus-defending center fielder is something that even contenders can deal with, even if you’d like some more offense.
Taylor is organizational depth. He turns 25 next season and has only pitched 50 innings above A-ball. Corona was an international signee last year so he’s not near contributing to a contender like Houston.