Diop poised for Blues bow David Murphy and Curtis Davies are hopeful of being fit for Birmingham's home clash against Leicester while new signing Papa Bouba Diop has been granted clearance to play. Left-back Murphy has trained all this week having missed the last month with a hamstring injury, while centre-back Davies joined in with his team-mates on Thursday having escaped with only a minor ankle injury last time out against Huddersfield. Midfielder Diop agreed a one-month deal with Blues during the international break and, after a delay, was finally issued with his visa on Thursday before his move was approved by the Football Association and Football League. The 34-year-old has spent the last week in France and been unable to get vital match fitness under his belt, meaning he will only be able to start on the bench against the Foxes. Nikola Zigic starts a three-match suspension following his dismissal against the Terriers, while Stephen Carr (knee), Paul Caddis (shoulder), Pablo Ibanez (broken toe), Akwasi Asante (hamstring) and Ben Gordon (knee) are all sidelined. Jamie Vardy is a major doubt for Leicester ahead of the trip. The former Fleetwood forward has missed much of training this week through illness and is likely to be absent when the second-placed Foxes resume npower Championship action at St Andrew's. It means one of Martyn Waghorn, Marko Futacs or Jeff Schlupp could partner in-form David Nugent, who has scored five goals in his last seven games, in attack. It is highly likely that centre-half Sean St Ledger will be unavailable due to the hamstring injury that forced his recent withdrawal from the Republic of Ireland squad. Midfielders Andy King and Anthony Knockaert have returned from international duty unscathed. Paul Gallagher is back at the King Power Stadium following his month-long loan spell at Sheffield United and the forward is another option for manager Nigel Pearson, whose team have won their last five league matches.