The Mets are likely down four starters against Patrick Corbin, who has been one of the best lefthanders in the National League during the past two seasons. Dangerous righthanded DH Yoenis Cespedes left the team and Robinson Cano, Amed Rosario and Jeff McNeil all were injured in the Mets' victory against the Braves Monday. Cano and McNeil are the Mets' two leading hitters this season. 
The Under is 16-6-2 (73%) the past 24 times the Mets have gone against a southpaw starter. 
The Nationals figure to be swinging rusty bats as they've been idle the past four days. Washington's offense has been slow during the early part of the season ranking 26th in the league in runs scored. 
Mets starter Steven Matz's velocity is up this year. He should be able to handle a rusty and slow-out-of-the-gates disjointed Nationals lineup that remains without their most feared hitter, Juan Soto.