The Mets are a below average team both offensively and pitching-wise. The Nationals have begun the season slow, but now their offense is healthy. I expect them to make a move. Having Juan Soto back in the lineup makes a difference. Washington is averaging 8 runs during its last three games.
I like Nationals starter Austin Voth. I think he's below-the-radar. He had a 3.30 ERA and 1.05 WHIP last season. He has a 1.80 ERA this season while entering his prime. 
David Peterson hopes to show he can be a reliable starter for the Mets. Peterson is getting a chance because Marcus Stroman, Michael Wacha and Noah Syndergaard are all out. 
My preference is Voth. It's a bonus to get him at a plus price in this matchup.