Freddie Prinze Jr. just UNLOADED on Kiefer Sutherland -- saying he HATED working with Kiefer on "24" and calling him the "most unprofessional dude in the world."
Freddie made the comments at Comic-Con -- telling ABC News Radio his experience on "24" in 2010 was so bad, he wanted to quit acting altogether.
"I did '24' ... it was terrible. I hated every moment of it. I just wanted to quit the business after that. So, I just sort of stopped."
He then turned his sights to Sutherland -- saying, "Kiefer was the most unprofessional dude in the world. That's not me talking trash, I'd say it to his face. I think everyone that's worked with him has said that."
In fact, Prinze Jr. still hates Kiefer so badly, he took a shot at the actor for being short -- saying, "I went and worked for Vince McMahon at the WWE, for Christ's sake … but, at least he was cool and tall. I didn't have to take my shoes off to do scenes with him, which they made me do [at 24]. Just put the guy on an apple box or don't hire me next time. You know I'm 6 feet and he's 5'4."
He clearly changed his tune ... back in 2010 Prinze had nothing but good things to say about working with Kiefer.
Freddie Prinze Jr.
BASHES KIEFER SUTHERLAND
'Most Unprofessional Dude In the World'
7/28/2014 10:26 AM PDT BY TMZ STAFF
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