Downing, who is currently sidelined through injury, is one of a number of Boro players expected to move on in the wake of their relegation from the Barclays Premier League.

The England international was linked with a move to Tottenham Hotspur in the January transfer window with Downing having a transfer request rejected by the Teessiders.

Gibson will not stand in Downing's way this summer if they receive a suitable offer, but appears to have ruled out a switch to Tottenham for the winger stating that a deal will only happen if it is one of the top four that comes in for the player.

"We had an unspoken agreement that if the right club came in, and I believe Stewart is a top-four club player, then we wouldn't stand in his way. It's a short career," said Gibson.

"There comes a point where a player must sit down and, without emotion, make a decision about their career.

"He has five or six years left at the top. Can I offer him European football? No. Does he deserve European football? In my opinion, yes."