He arrived at Rangers from Everton in a £250,000 deal in August 2003, but has fallen out of favour and had been told his contract would not be extended past this summer.
Chester City failed with a £125,000 bid for him last week, with the winger rejecting a move to the League Two strugglers - but a move to third-placed Swansea appears more tempting.
QPR boss Ian Holloway said: "He's not happy at being left out and his deal is up at the end of the season so it's down to whether he can agree terms.
"He hasn't really performed and that's why he hasn't been involved, but he's still a good player.
"I rate Kevin McLeod highly and believe he can come again."