James McAvoy was bullied on the “Band of Brothers” set by one of his co-stars.

The actor confirmed on “Watch What Happens Live” Monday that the man in question was one of the people featured in the cast photo Andy Cohen showed viewers.

The image featured Donnie Wahlberg, Kirk Acevedo, Scott Grimes, Neal McDonough, Philip Barantini, Adam James, Frank John Hughes and Ross McCall.

While McAvoy did not name the bully, he confirmed it wasn’t David Schwimmer.

The “Shameless” alum, 47, went on to describe the experience, which took place his first day on set of the 2001 show while filming “one of those scenes with everybody in it … at a bar.”

He explained, “All these guys were in it for nine months, 10 months, and they get one line in one episode and one line 10 episodes later. They were all pissed. I come in for one episode, and I’ve got an arc and scenes. I’ve got tons of lines.”

McAvoy, notably, played Private First Class James W. Miller in the fourth episode, “Replacements.”

He remembered, “So, one of the guys in that picture decided to bully me — on my first day as a professional actor out of acting school. He got him and his buddies to just stand pointing at me and laugh at me for, like, three minutes.”

Cohen, 58, chimed in to call the moment “terrible.”

The “X-Men: First Class” star noted that Dexter Fletcher and Robin Laing pulled him aside at the time and saying, “Come hang with us, man.”

While McAvoy dubbed that day on set a two out of 10, he clarified that the rest of the experience was a nine.

Reps for Wahlberg, Acevedo, Grimes, Barantini, James, McDonough, Hughes and McCall did not immediately respond to Page Six’s requests for comment.

Elsewhere during his “WWHL” appearance Monday, the Golden Globe nominee reflected on other projects from his career.

He called “The Near Room,” his 1995 film debut, an “amazing” time besides being “terrified.”

As for doing “The Chronicles of Narnia” a decade later, he raved over his time in the movie as a 10 out of 10.

“I played the horny goat guy,” he said. “I had like six months in New Zealand with 20 days work. So I just went hiking and camping. It was awesome.”