Mets pitcher Marcus Stromam seems to think the Yankees made a mistake by not acquiring him at the MLB trade deadline — at least according to his social media activity.

Stroman endorsed a series of tweets Tuesday night — during the Yankees’ 4-1 loss to the Astros in Game 3 of the ALCS — that criticized the Yanks for not beefing up their starting rotation at the deadline.

“This is the series when the @Yankees regret not making a move to get a stud pitcher,” wrote Pierce W. Huff in a tweet “liked” by Stroman.

The Long Island native Stroman seemed bound for the Yankees this summer, but the Blue Jays instead dealt the starter to the Mets, who missed the postseason.

“We were interested in Stroman but we didn’t think he would be a difference maker … we felt he would be in our bullpen in the postseason,” Yankees general manager Brian Cashman told Yahoo Sports last month.

One Twitter user mockingly replied to a highlight of Yankees starting pitcher Luis Severino giving up a home run Tuesday night with Cashman’s reasoning for passing on Stroman.

Stroman “liked” that tweet as well.

Stroman seemed taken back by Cashman’s snub when the GM’s comments were first published. Then, Stroman tweeted a graphic showing his superior statistics compared to the Yankees’ starters.

The 28-year-old went 10-13 with a 3.22 ERA this season split between the Blue Jays and Mets, while starting pitching has been considered the Yankees’ weak spot all season.