Cahill is now recovering at home after being discharged from hospital earlier in the week.
It has been widely reported Cahill, who had been tipped to win a place in England's World Cup squad, will miss the rest of the season.
Coyle insists that is premature and has not given up hope he could return before the end of the campaign - but a comeback is not the immediate concern.
The Scot said: "We will leave no stone unturned to make sure of Gary's welfare. That is the priority.
"We have been speaking to specialists in this field to try to do the best by Gary.
"I said we suspected he would be out for a period of time, probably a couple of months.
"Then obviously because in a couple of months there's not long to go, it all of a sudden became he's out for the season.
"All I would say is, first and foremost, we are doing everything we can to help Gary.
"Once we know his wellbeing is assured we will look at the football side of things.
"He's very comfortable at home, albeit he can't do anything in terms of physical exercise, which is right.
"We'll revisit it in a couple of weeks, have a word with the specialist and see where he is at with it."
Former England Under-21 international Cahill, a £5million signing from Aston Villa two years ago, had been one of Bolton's most consistent players this season.
The club first became aware of his problem when he was forced to pull out of last Saturday's Premier League draw with Fulham on the morning of the game.
His absence is a blow to the Trotters as they battle against relegation from top flight and prepare to host Tottenham in the FA Cup fifth round on Sunday.
Coyle believes that tie at least offers a good escape from league action and feels a positive result could turn the season around.
"Nothing breeds confidence more than winning matches and these games give us an opportunity to do that," Coyle said.
"We recognise we are playing a good side but you want to be winning games and scoring goals.
"If you can do that against the quality of Tottenham Hotspur, I think that would give everybody a big boost."
Coyle has also leapt to the defence of his captain Kevin Davies, who has been asked by the Football Association to explain his recent comments about referee Mark Clattenburg.
Davies, who has been booked four times by Clattenburg this season, felt he had a legitimate winning goal against Fulham disallowed because of "something personal".
Coyle said: "He is such an honest lad and he plays that way. Yes, he is a physical player but he is a quality Premier League player.
"I believe he is probably fouled against more than he gives out.
"Against Fulham he had an absolute stonewall penalty and the referee was well positioned to give it but never did.
"Then he scores a perfectly good goal which the whole world has seen a minute from the end of the game.
"I think then after the game there is emotion, frustration.
"He is asked to give his assessment on it and he did.
"I think it is a bit harsh that he is then asked to explain his comments when he speaks honestly.
"I think there has got to be a level of understanding with how emotional the game is.
"Without emotion the game would be poorer and I'm not just saying this because he is my player."