"I think we're all in such shock," Dave Coulier tells ET of Alan Thicke's sudden death on Tuesday at 69.
Thicke recently guest starred alongside Coulier on the second season of Netflix's Fuller House, but their friendship started long before that. "Alan and I go a long, long way back and the common bond was hockey," Coulier recalls. "We had a lot of things in common, Candace Cameron Bure of course, Jeff Franklin -- the creator of Full House. Alan and I sat next to each other on the bus rides, in the dressing room, we were both on sitcoms, we both had sons who played hockey. So, there was a lot in common there."
Coulier admits that he's yet to come to terms with his friend's death. "I had bad dreams all night last night," he says. "I guess my brain just can't process this yet, and it's so surreal. I hope that once the reality settles in, we're all able to come together and give him the tribute that he deserves."
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The 57-year-old actor confesses that when he first heard the news about Thicke's death, he initially didn't believe it. "I got a text from a fellow hockey player. I thought it was one of those internet hoaxes," he explains. "I've been dead a few times on the internet, so right away that was my first thought. 'Oh, this has got to be a joke,' and then I went online and there it was."
He adds, "My heart just dropped."
As for what he will remember most about Thicke, Coulier says the actor had a great sense of humor. "I will always remember Alan as a funny guy who always had a joke or a funny story, who loved his family, [and] loved hockey," he says.
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Thicke, who was best known for playing Jason Seaver on Growing Pains, suffered a heart attack while playing hockey with his 19-year-old son, Carter, on Tuesday. He was pronounced dead at Providence St. Joseph's Medical Center in Burbank, California.
"When he passed away, he was playing in a pickup in Burbank," Coulier continues. "I said to someone yesterday, 'If I could die playing hockey, that would probably be one of the happiest days of my life."
Coulier's Fuller House co-stars have also been paying their respects to Thicke on social media. His son, Robin Thicke, also paid tribute to his father, calling him the "greatest man I ever met." Here's a look at the singer's heartfelt message for his father:
Reporting by Tracie De La Rosa.