David Wright and David Norris are facing late fitness tests prior to Saturday's trip to Reading. The Blues are already without Jon Walters and Moritz Volz, but skipper Gareth McAuley is back after suspension.
Wright needed four stitches in an ankle injury after Tuesday's 0-0 draw at Wolves and the wound is currently swollen and there is some bruising around the joint. Town will leave it as late as possible before making a decision on the right-back.
If Wright fails to make it, Alex Bruce is likely to come into the side with Jaime Peters again included in the squad as cover.
Norris has a calf strain but it is hoped that the problem will improve enough for the ex-Plymouth man to take his place in the side. Moritz Volz will undergo surgery on his groin injury on Tuesday and is expected to be out for around a month.
Ben Thatcher will continue on the left and Richard Wright in goal, but the Town management have decisions to make at the centre of the defence.
Iván Campo and Pim Balkestein impressed at Wolves, but captain Gareth McAuley is likely to return to the side, probably in place of the Dutch youngster.
Assistant manager John Gorman says it will be difficult to drop anyone after the performance at Molineux: "It's a tough decision because they all played so well, the whole team played well as a defensive unit.
"We've now got to make a choice, do we give one player a rest or do we leave Gareth out? It's nice to have that problem, it's a positive problem."
In midfield, the Blues will be without Jon Walters for the rest of the season after he ruptured ankle ligaments in the first half at Wolves.
Boss Jim Magilton has various options in Walters's absence. Jon Stead has played a similar role to Walters wide in the past, although usually on the left, while Danny Haynes is available again after his hamstring injury.
Town again look set to use a their 4-5-1/4-3-3 formation with David Norris, assuming he's fit, Tommy Miller and Alan Quinn the trio in the centre and Luciano Civelli on the left. If Norris fails to make it Owen Garvan is likely to come in ahead of Veliche Shumulikoski.
John Gorman feels Town's away formation has been unfairly criticised in some quarters: "I hate people saying we just play one up front, we play three up front. Do Manchester United play with just one up front? No. The top teams in Europe play that way too. It is a great way to play.
"Luca is an out and out winger and Jon Walters is a recognised forward, so is Kevin Lisbie. It is not a negative way and we can change it when we bring Pablo Couñago in, he plays in the hole and Jon Stead can come in. It is a good system because we get the solidarity and we can break from it.â€Â
Lisbie is likely to be the central striker with Couñago probably used from the bench at some stage.
Reading are currently third in the table on 64 points, 13 points ahead of the Blues in 10th. The Royals are four points behind Birmingham in second with two games in hand.
At home they have won 12, drawn four and lost three this season. Steve Coppell's men are going through a bit of a rocky patch and have won only one of their last seven games.
Dave Kitson and Glen Little have returned to the Madejski Stadium on loan this week, having left for Premier League Stoke and Portsmouth in the summer.
Reading have Michail Antonio (ankle), Ivar Ingimarsson (knee), Graeme Murty (calf) and Sam Sodje (knee) all sidelined at present.
Town have just about had the better of the Royals historically, the Blues winning 19 encounters (including the only cup meeting between the sides) and Reading 15, with eight matches ending in draws.
The teams last met at the Madejski Stadium in 2005/06 when a Richard Naylor own goal and one from Kevin Doyle gave the home side a 2-0 victory.
Town are yet to win at the Royals' current ground, the Blues' last win in Reading coming in November 1997 at Elm Park when goals from Matt Holland, David Johnson, James Scowcroft and Richard Naylor saw George Burley's men to a 4-0 victory.
At Portman Road earlier this season, the Blues won 2-0, Jon Stead and Jon Walters netting the goals.
No current Town player has spent time with Reading, while Dan Harding, currently on loan at the Madejski Stadium from the Blues, is the only member of the Royals squad to have played for Town. The left-back is yet to be involved in the first team 16 since moving in January.
Reading's Chelmsford-born midfielder James Harper has friends who are Town fans and has gone to chat with them at the front of the stand at the final whistle after previous Town-Reading games.
Saturday's referee is Michael Oliver from Northumberland, who has shown 77 yellow and four red cards in 31 games so far this season. Oliver has not previously refereed a Town match.
Likely squad: R Wright, D Wright, Thatcher, Bruce, Peters, McAuley, Campo, Balkestein, Quinn, Norris, Miller, Garvan, Shumulikoski, Civelli, Haynes, Stead, Lisbie, Couñago, Bowditch.