Lee, 23, suffered a double fracture of his lower right leg during a pre-season friendly with Newport County in July and was estimated to be out for nine months.
Coyle, though, has been encouraged by the South Korea international's recovery so far, and is optimistic he could be back in action by March 2012.
"At this moment in time, he's doing better than I would have envisaged," Coyle told the Bolton News.
"I don't want to get ahead of myself but I don't think it will be as bad as we first thought - i.e. the whole season - but what part of it he comes back is still very much up in the air.
"We could get him back March, maybe, but he's certainly doing well."
Lee joined Bolton from FC Seoul for £2.2 million in 2009 and has impressed at the Reebok Stadium since the switch, scoring seven goals in 65 Premier League appearances.