Davies has impressed the Reebok Stadium faithful with his displays since joining the Premier League side from Wolves during the winter transfer window.
Trotters boss Gary Megson is still waiting to discover how long the youngster will be on the sidelines, but remains hopeful Davies could play some part before the end of the season.
He told the club's official website: "Mark is struggling. We don't know exactly how long it will be for but we'd consider it long term.
"We hope he will be back before the end of the season. This kind of thing happens, but he will get over it because he's a young lad."
Bolton remain embroiled in the battle to avoid relegation from the Premier League and, despite sitting 12th in the table, are just four points above the bottom three.
Davies' absence at such a crucial stage of the campaign will be a blow to Megson's hopes of ensuring the club retain their top-flight status.
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