"Eric Braeden is a D-Bag. the actor, (Robin's dad) agreed to a cameo, then last night bailed, saying the part wasn't 'substantial' enough," Harris tweeted early Friday.
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Twin Peaks and Reaper alum Ray Wise will replace Braeden, according to Harris.
"[Wise is] a fantastic actor who makes any part 'substantial,'" he tweeted. "Super excited to welcome him to the family!"
Harris, however, retracted his comments against Braeden a few hours later. "Now I feel bad for the D-bag comment," he wrote. "Don't know the guy personally. I'm just fiercely protective of our show."
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"I really don't know who that fellow is. He's a guy who stars in that series," Braeden told Entertainment Weekly following Harris' initial comments. "The choice of words bothered me. He seems to me like a young whippersnapper... who's received a few awards [and] is now suffering from the first sign of hubris. I've been in the business for 50 years. I've seen people come and go and I'm still here."
Braeden — who last year temporarily left Young & the Restless over a contract dispute — first guest-starred on Mother two years ago as Robin Charles Scherbatsky Sr., Robin's dad who was so desperate to have a son that he named her Jr. and raised her as if she were a boy.
The 69-year-old actor attributed his last-minute decision to pull out of the cameo to medical reasons. "First of all, I came back from hip surgery. I was off for three weeks," Braden told the magazine. "I've doubled my work, 30 to 50 pages a day for me, alone. Everyone knows that I'm exhausted. I was not about appear on a show for two lines, because that's what it amounted to."
The actor's exit from Mother is not too surprising: He told TVGuide.com in 2008 that he didn't want to do the show in the first place.
"I was talked into it by family and agents saying it was one of the highest-ranked shows and this and that," he said then. "And I enjoyed it enormously."
On Friday, Braeden reiterated that feeling. "I truly enjoyed working there last time," he told EW. "The cast and crew and producers couldn't have been nicer. "
Emails to CBS and Braeden's rep were not immediately returned.