The Swede is enjoying a purple patch after a difficult time and has scored eight goals already in a thrilling campaign.
Coyle said: "If players are playing well it is only natural bigger clubs will cast an eye on them. That is the nature of football and I am relaxed about it.
"Until those bids come in, it is all hypothetical. When they do we will give them respect and make a decision. I do not get caught up in it too much and beat myself up. Johan knows that.
"If it was a club of a similar size to Bolton I believe he would stay here. If an elite club came in Johan would be crazy not to think about it. I have no problems with that. Johan is well within his rights to do what is right for himself and his family. What I will do game by game is try to get the best out of him."
Coyle added: "Phil has had talks with Johan's representative and that will be on-going. Johan has been terrific from day one and if they decide they want it to run its course into January, then so be it."
Source: PA
Source: PA