Town will be without midfielder Gavin Williams when they travel to Crystal Palace on Saturday. The Blues also have major doubts over Richard Naylor and Alan Lee.
Williams a damaged pelvis ligament in Tuesday's game at Stoke and Town are unsure how long the Welshman will be out of action.
Magilton says he won't risk Lee or Naylor if there is any doubt about their hamstring and toe injuries: "We have to be careful with Alan. He played last season with a tight hamstring and it went in the next game, which meant a month out.
"We will make a late call on him and it's the same with Richard Naylor.”
Naylor looks most likely to be on the bench with Alex Bruce back from a two-match ban. Fabian Wilnis will once again captain the side - Jason De Vos is still on the sidelines with his cracked metatarsal - with Bruce alongside the Dutchman at the centre of the defence.
David Wright will switch to right-back with Sito not in the squad, his girlfriend having given birth to their first daughter overnight. Dan Harding will continue at left-back and Lewis Price will once again be in goal.
Magilton will have to decide whether to employ the five-man midfield used at Stoke or switch to a four. If it's a five, Sylvain Legwinski could again take up the more advanced role he filled on Wednesday, with Matt Richards joining the Frenchman and Owen Garvan in the middle. Jaime Peters will be on the right with Gary Roberts on the left for the final time before a one-game ban for reaching five bookings.
Jon Walters could again be used as a lone striker with the Blues not keen to risk Lee for fear of aggravating his hamstring injury further. If Magilton chooses to go with a front two, Billy Clarke may be a more likely option.
Palace boss Peter Taylor has one or two injury concerns with midfielder Stuart Green hurting his shoulder at Sunderland earlier in the week.
Recent signing Paul Ifill has a wrist problem and youngster Rhoys Wiggins is out. However, Danny Granville and Gary Borrowdale are back in training having been sidelined for a while. Midfielder Marco Reich and former Town loanee Jon Macken left Selhurst Park during the transfer window.
Taylor says his Town counterpart has assembled a decent squad: "Jim will have learnt a lot this year as a new manager and he's got some good players there.
"They are a very good footballing team and I was speaking to Roy Keane after the game on Tuesday as they played them last and he said they played 4-5-1 there, as they did at Stoke.
"They will play a lot of football though, and they have some very good footballers in the midfield, so it's going to be a hard day for us.
"We have to match them every way we can in midfield because if we don't they can out pass you."
The Eagles have former Blues James Scowcroft and Shefki Kuqi in their first team squad, along with ex-academy striker Charlie Sheringham.
Town fans can purchase tickets on the day of the game from the Selhurst Park visitors' box office. Once again Palace is the most expensive trip of the season with adult tickets £30, while concessions and under-16s are charged £18.
Saturday's referee is Premiership official Martin Atkinson from Yorkshire, who has shown 65 yellow and three red cards in 25 games this season. Atkinson's last Town game was the 3-1 home victory over Plymouth in November 2005.
Squad: Bruce, Casement, Clarke, Garvan, Harding, Haynes, Lee, Legwinski, Naylor, O'Callaghan, Peters, Price, Richards, Roberts, Supple, Walters, Wilnis, Wright.