The central defender was expected to be sidelined for several months, ending his dreams of making Fabio Capello's England squad for the trip to South Africa.
However, Coyle remains hopeful the former Aston Villa man could be back before the season draws to a close
"I said he'd be out for a number of months," said Coyle.
"I would love to think there's a glimmer of hope he might be back, primarily for Bolton because of the position we're in, but equally for his own personal goal, which is to make the World Cup finals.
"I will leave no stone uncovered to make sure we are doing anything we can to help him and we'll take it from there.
"Gary is back at home now. He came home on Monday night. He went back on Tuesday for more scans to check out the other side of his body to check everything was OK. It was fine, so that's a positive."
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