Cahill has long been touted as a target for Arsenal and there are plenty of others who are also interested in the possibility of luring the 25-year-old away from the Reebok Stadium.
"You don't want to lose your best players and Gary is fantastic," said Knight. "As yet, no one has come in for him, which is a blessing. We want to keep him but there are a lot of bigger clubs out there and if someone comes in for the right money, no one can stop him."
Not that Knight would view Cahill's departure as insurmountable.
David Wheater's arrival from Middlesbrough has already provided additional competition for places and, as the 31-year-old points out, with 69 Premier League starts from a possible 78 over the past two seasons, he has been a fairly consistent presence in the Trotters' line-up.
"Hopefully I have done enough to get my place on August 13," he said.
"David Wheater has given us additional options anyway but we have strengthened it up all over the park.
"If someone isn't playing too well the manager (Owen Coyle) can now bring people in."
Bolton appear to be having another push at trying to secure the services of Shaun Wright-Phillips from Manchester City, although wages could still prove a major stumbling block.
Interest in Liverpool striker David Ngog and Cameron Jerome of Birmingham has so far failed to turn into anything concrete, which means Bolton are set to tackle newly-promoted QPR at Loftus Road - if the violence in London has subsided by Saturday - with the men already at Coyle's disposal.
Source: PA
Source: PA