The 25-year-old Ghana international will spend the rest of the campaign at Al-Ain after months of speculation that he could leave Wearside after just one season finally came to a head.
Manager Steve Bruce was forced to admit defeat in his efforts to refocus his £13million-plus record signing on the club just 48 hours after believing he had done just that.
Asked if Gyan could return to the Stadium of Light to see out the final two years of his contract, the manager, who only learnt of the latest development at 9.15am on Saturday morning, replied: "He can, but I can't see it. He's been unsettled now, if we are being brutally honest, for weeks and months.
"Real Madrid was the first one, which I laughed at five months ago, but it started with that and it's ended up with the United Arab Emirates.
"It's disappointing, but we draw a line under it. The one thing I will say is I have never ever kept a person at a football club who didn't want to be there, and that belief will always be there whether I manage Sunderland or whether I manage any other club.
"If you don't want to play for the team and play for the club and play for the jersey, then what's the point?
"We decided to cut the best deal possible and we move on."
On Friday, Bruce hit out at the "parasites" he believed had turned Gyan's head throughout a summer littered with rumours about potential interest in him.
Twenty four hours later He returned to the theme with some venom after seeing the pressure finally tell.
He said: "People surround themselves - agents going to visit them, five of them on Monday going to visit him in his hotel room, threatening him and the rest of it.
"Who knows? Who knows what's gone on around him? That's one thing when they leave you, I, can't control. It's very difficult.
"I had a conversation with Gyan 48 hours ago with his agent. He shook me by the hand, get on with it, he wanted to play here, stay here because the nonsense had gone on for too long.
"I will let everybody else make their conclusions. To go and leave the Premier League for the United Arab Emirates, I will let you make your own conclusion to that.
"Sometimes things disappoint you in football which are quite unbelievable, but there you go.
"What are you going to the United Arab Emirates for? No disrespect to the country, of course."
Asked if he felt let down by the striker after handing him his big chance to play in the Barclays Premier League, Bruce said: "I have been in it a long, long time. Nothing surprises me anymore."