1) Ranking the options for the final spot in the postseason rotation: Carlos Carrasco
Carlos Carrasco's Mets tenure got off to a rough start last season. He missed much of the campaign with a torn hamstring and I believe he was rushed back and did not pitch well at all.
This season has been another story. He has looked a lot like the Carlos Carrasco the Mets traded for alongside Francisco Lindor.
Outside of a rough start in St. Louis and a horrible month of June, Carrasco has been a consistent mid-rotation level starter for much of the season.
Carrasco has allowed three earned runs or less in 19 of his 24 starts. He's given the Mets a great chance to win most of the time that he pitches, and they've won 15 of his starts because of that.
Overall, Carrasco has gone 13-6 with a 3.94 ERA in 24 starts. His 3.64 FIP suggests he's gotten rather unlucky as well.
Peterson has out-pitched Carrasco slightly, but I'd lean with the experience and the guy who doesn't walk many. Carrasco has made three career postseason starts so he knows what it's like to pitch in a crazy atmosphere.