Wigan resigned to losing Valencia
Wigan have already had one offer from Real Madrid for the 23-year-old, but he has also attracted the interest of other clubs, Bruce added.
"It's inevitable that the lad will be leaving in the summer as there are clubs queuing up, jostling for position," Bruce told the Wigan Evening Post.
"I won't lie to fans about that. Of course I would love to keep him, but it's going to be impossible for that to happen.
"I have only worked with the kid for 18 months but he has got a special talent. He's a very good player," he said.
Bruce said a hamstring injury is likely to keep Valencia out of Wigan's last game this season against Portsmouth on Sunday.