Jon Niese will remain tomorrow afternoon's starter against the Rockies, and Matt Harvey will pitch Friday night against Washington.
The Mets had to bump somebody to Saturday, whether it was Hefner or Aaron Laffey. Collin McHugh pitched 5 2/3 innings for Las Vegas last night, and he was the only other logical candidate for that start. The only good news about today's game being postponed is the Mets do not need to use a fifth starter for one turn through the rotation, meaning they can skip Laffey for now.
It's worth noting Zack Wheeler will start for Las Vegas on Friday night. His next start would be the following Thursday, April 25. The Mets will need a fifth starter on April 27 against the Phillies. They could still turn to somebody like Laffey or McHugh for that game, or even Shaun Marcum if he's ready to go. But if Wheeler looks good on Friday and something prevents Marcum from being activated, I wonder if Wheeler might enter the discussion as a candidate to start that April 27 game in New York.