Because the Mets will have to play at an American League park for at least two games, they will need to figure out who their designated hitter will be. There are plenty of eligible candidates, and it’s possible that the Mets will alternate DHs' from game to game.
Yoenis Cespedes has played left field and center field for the Mets since he was brought in at the deadline and has done so very well. He has a cannon for an arm, but because he tweaked his non-throwing shoulder in Game 4 of the NLCS it’s possible that Terry Collins will treat the Cuban slugger with caution going into the World Series until he’s positive that he’s healthy.
Michael Conforto, who will likely see a lot of playing time as the Royals’ starters are all right-handed, is usually lifted by Collins late in games for Juan Lagares for defensive purposes (Conforto isn’t a bad defensive fielder but Lagares has a Gold Glove), so he seems like a logical candidate to be the DH.
After those two power outfielders comes Michael Cuddyer, who has had a disappointing year for the Mets at age 36. He hasn’t seen much playing time since his blunders in the outfield early in the NLDS. Because the Mets will be seeing a lot of righties in this series, it looks like Cuddyer will be riding the pine most of the way.
A fringe candidate for the DH spot is Juan Uribe, who has yet to play this postseason due to a chest injury. Uribe played a lot while David Wright was rehabbing, but his role was diminished once the team captain came back in late August. In 44 games as a Met, Uribe hit only .219 but had six home runs.