Watch: Brian Cox regrets his recent comments about Johnny Depp
The 75-year-old actor called Depp, 58, "overrated and overblown" in his autobiography and mocked his performance in Edward Scissorhands before claiming his career was dwindling.
"That was what happened, and I sort of regretted it. Because I'm not like that normally; I was just being a bit glib, a bit flip."
Cox wrote in his memoir, Putting the Rabbit in the Hat: "Personable though I'm sure he is, is so overblown, so overrated.
"I mean, Edward Scissorhands. Let's face it, if you come on with hands like that and pale, scarred-face makeup, you don't have to do anything. And he didn't."
He added: "And subsequently, he's done even less."
Cox said of not being part of the Disney Pirates Of The Caribbean franchise: "It would have been a money-spinner, but of all the parts in that film it was the most thankless, plus I would have ended up doing it for film after film and missed out on all the other nice things I've done."
The Scottish actor has previously told Yahoo he did not mean to disrespect Depp in his memoir.
He said: "What certain people accused me of was my lack of respect, and I really do not disrespect anybody involved in this profession because I know how difficult it is."
Cox continued: "Now, I may have reservations about their talent, but I certainly don't disrespect them. And my reservations about Johnny Depp are minimal — absolutely minimal.
"You know, I do think he's sometimes overblown, but I actually think he's also done some considerable work. Some of his work has really been extraordinarily good."
Depp's work in Hollywood has dried up in recent years, in the wake of the high-profile fallout from his relationship with Amber Heard and her allegations of domestic violence against him.
The actor lost a libel action against The Sun in November 2020 over an article in which he was described as a "wife-beater".
In the wake of the case, Depp was dropped from his role as dark wizard Gellert Grindelwald in the Fantastic Beasts franchise and replaced by Mads Mikkelsen.
Depp recently signed on for one of his first major roles since the court case, playing King Louis XV in a French drama set to shoot this summer.