John Stamos 'not ready to say goodbye' to Bob Saget

John Stamos is "not ready to say goodbye" to his late co-star Bob Saget.

The Full House actor and stand-up comedian died suddenly at the age of 65 on Sunday. His cause of death has not yet been revealed.

Taking to Instagram on Tuesday, Stamos posted a snap of himself with his longtime friend, and in the accompanying caption, explained that he is in shock over Saget's passing.

"I'm not ready to accept that he's gone - I'm not going to say goodbye yet," he began.

Stamos went on to share how he has been imagining a scenario in which Saget is still alive following his stand-up set in Jacksonville, Florida on Saturday night.

"I'm going to imagine him out there, still on the road, doing what he loves with all his heart and humor. He's standing on stage, killing! Another two-hour set in front of a couple hundred of the luckiest people on the planet. They're laughing so hard, they weep," the 58-year-old continued. "On his way to the hotel, he calls his beautiful, loving wife, Kelly. He says he feels 26 again, alive! Then asks her to fix up a picture he wants to post. She tells him it doesn't need fixing, and tells him how handsome he is. He tells her he loves her with every bit of his heart. And when he gets to the hotel to put his head on the pillow, he misses his daughters, his family, his friends. God, he loves us all so much. And he goes to sleep dreaming of when we'll all meet again - and he's smiling."

Stamos concluded his post by stating that he knows in his heart that his pal "is smiling".

"I'm just not ready to say goodbye yet. Maybe tomorrow. Maybe," he added.

Saget is survived by his wife Kelly Rizzo as well as his three daughters from his marriage to ex-wife Sherri Kramer.