Last season's top scorer is into the final year of his contract and did not travel to Belfast for Wednesday's Champions League qualifier against Cliftonville.
Celtic expect Hooper to leave, but Neil Lennon says there are two clubs in for him and QPR boss Harry Redknapp told Sky Sports News a deal to bring him to Loftus Road is not done yet.
Redknapp said: "He's a player we've made an inquiry for, but I don't know where we're at. We're not close to it at the moment.
"He's a player we like, but it's whether they want to sell him and whether we can pay enough money for him, basically. If not, we move on."
Lennon said: "There are a couple of clubs interested, talks are ongoing. I expect the move to go ahead. I don't know which club or what price but I'd expect it to be over the next week or so".
Earlier, Lennon's assistant Johan Mjallby said: "It looks likely that Gary Hooper will leave the club but the final word has not been said, so we will see.
"A bid came in last night, but I don't know how the club has responded to it. It's an increased bid but I don't know if it's good enough. That's something you'd have to ask the manager, chief executive and board."
Mjallby blamed injury for Hooper's omission from the travelling party, saying: "He's been carrying a groin strain so he's not fit."
Celtic have already sold another of last season's top performers, Victor Wanyama, and Mjallby said: "We definitely want to strengthen. We're always on the lookout, especially after losing Victor."