Prior to his departure from Burnley, Coyle had been hoping to sign Arsenal midfielder Wilshere on loan, however, he is not currently planning an approach for the youngster in his new role.
"He is a very good player, but it is something I have not looked at," said Coyle of Wilshere.
"We obviously tried at Burnley, but with Arsenal's injuries it was put back and now they have got other injuries there as well so he might not be available.
"What I must do is assess the squad I have and it would be wrong of me not to give them all a fair crack - accepted that the transfer window is such a small space of time.
"So if there are areas where we can help the team, then that is what we will do."
Coyle also confirmed he will not be pressed into selling Cahill, with the £15million-rated centre-back having been linked with the likes of Manchester City and Everton.
He added: "We don't have to sell anybody to generate a transfer budget.
"I am looking at Gary Cahill and I believe if he shows the qualities he has, then he can make the England World Cup squad.
"That is a motivation for him. He is a top player and hopefully we will see him at his very best here."
Arsenal 4/7, Draw 11/4, Bolton 11/2