"Schwimmer was fine with the monkeys for the first couple of episodes and happy to be there," Morris said. "But people would laugh at the monkey and I think he got jealous because it wasn't him getting the laughs. He seemed to get a little bitter about them being there after that."
"And of course the monkeys didn't like working with him after he turned on them," he continued. "My colleague who also worked on the show says that people would laugh at the monkey and throw Schwimmer off. He's not the kind of actor who can improvise."
“It got to the point where he just really resented the monkey being there."
Morris' remarks came after Schwimmer claimed the monkeys would rub their grub-infested hands on him on set during the recent "Friends: The Reunion" special on HBO. "It was time for Marcel to f--- off," the star added.
As Monkey recently died of cancer, Morris accused Schwimmer of "talking ill of the dead when he made those comments."
"I find it despicable for him to still be speaking ill of her," he told The Sun.
Morris also claimed Schwimmer once accused the monkeys of "throwing poop" at him and trying to bite him.
"I have never ever watched 'Friends' because of Schwimmer's comments about the monkeys," he said. "They didn't do any of that. None of it is true, when I was there none of that ever happened."
While Morris took aim at Schwimmer, he also applauded the "Friends" co-stars for working effortlessly with the monkeys. "The rest of the 'Friends' cast were nice," he claimed.
"The few times we worked with Matt LeBlanc he was great, he really liked the monkey and found it easy to work with it," he added. "Jennifer Aniston did a few scenes with the monkeys too and she was also great to work with."