Bolton defender Gary Cahill could be back in action in four weeks, despite earlier fears he could miss the rest of the season because of a blood clot.The centre-back had an scan on his arm on Thursday and Wanderers boss Owen Coyle says he is making good progress. [LNB]"Gary will go another two weeks without any contact but from that point he'll join in with the group," added Coyle. [LNB]Cahill, 24, who was taken ill on 5 February, had been tipped to make the England squad for the World Cup. [LNB]Coyle added: "Gary had an operation and the blood is now free-flowing, the clot is totally dissolved and the vein is in perfect order. [LNB]"I'm envisaging, fingers crossed without getting too far ahead of ourselves, that possibly Gary could be back within four weeks." [LNB]The Bolton boss also played up Cahill's chances of making Fabio Capello's England squad for the World Cup in South Africa this summer. [LNB]"Ideally I'd like him back earlier but we have to make sure Gary is fine," said the former Burnley boss, whose team are third from bottom of the Premier League and face fellow strugglers Wolves on Saturday.[LNB] In four weeks our fate may well have been decided, but this is good news because we need Cahill asap luckyPeterpiper "I have no doubt that if he gets back to the level he is capable of - without putting too much pressure on him - then I think he will be a real candidate." [LNB]Cahill, a former England Under-21 player, had been in excellent form for Wanderers before the blood clot and was linked with a move from the Reebok Stadium during the January transfer window. [LNB]He was part of the England squad for the World Cup qualifying victory against Kazakhstan in June 2009 but has yet to win a senior cap. [LNB]The defender joined Bolton from Aston Villa for £5m in January 2008. [LNB]Meanwhile, Wanderers striker Kevin Davies has been charged with improper conduct by the Football Association. [LNB]It follows his comment that referee Mark Clattenburg had "something personal" against him after ruling out what would have been his late winner against Fulham on 6 February. [LNB]The 32-year-old has until 12 March to respond to the charge.