"Nothing happens until January anyway because he's under contract to United. But I know there will be a lot of teams ringing up United after Sir Alex (Ferguson) said the other week that there would be plenty going out on loan.
"His phone will be red hot at this moment in time and whether Jonny will still be there in January I really don't know.
"But Jonny did brilliantly for the club, as did Danny, and it would be nice if we thought they could come back. But it's a big 'if'."
Keane added: "It was a nightmare giving them back, I have to say, because they'd settled in so well.
"But they were good professionals, hard trainers out on the pitch, half-decent with the media side and ready to put everything in."