Anthony Recker, a former MLB catcher who's been breaking down players and games for the league's network for the past year, made the comments on "MLB Tonight" on Wednesday ... seemingly taking a shot at Manoah's 6-foot-6, 285-pound frame.

"Show me you're willing to put a little more time in the gym," Recker said.

Manoah caught wind of the remarks a few hours later -- and he was clearly pissed over them.

"Hey @Anthony_Recker my job isn’t to please you," the 26-year-old said on his Twitter page. "You are an outsider you don’t know me or my work ethic. What I do in the gym has clearly worked check the numbers, sucks you can’t say the same for yourself."

Recker immediately tried to backpedal on the comments, telling Manoah his remarks were taken out of context.

Manoah, though, wasn't buying it ... adding, "Youre just like everyone else. Love to talk and then wanna say sorry when you get called out. If you wanna see how an All Star, 1st team All-MLB, and CY young finalist trains. Come meet me [at the gym]."

The right-handed flamethrower then shared a bunch of videos of him getting after it in the weight room.

Former Blue Jays pitcher Marcus Stroman later entered into the conversation -- slamming Recker for his comments as well.