The former Nottingham Forest star returns to the City Ground on Saturday with his Ipswich Town side looking to put a halt to a losing run which has marred a solid start to the season.
His old club meanwhile are hoping to put themselves back in the promotion picture by piecing together a string of wins on the back of Tuesday's narrow success against Middlesbrough.
Keane though feels that the play-offs at best are a realistic target for both clubs.
"When you look at the squads QPR and Cardiff have, if I were a betting man, I'd say they're the two red hot favourites to go up," he told BBC Radio Suffolk.
"It's a massive battle for the other four but we've got to stay in that battle."