Reading boss Brian McDermott will assess the fitness of midfield duo Jimmy Kebe and Mikele Leigertwood ahead of the clash.
Kebe has missed four games with a thigh injury and Leigertwood came off in last weekend's match with Derby with an ankle knock.
Yet McDermott, who has no other concerns, is hoping to have the pair available.
McDermott said: "We're working on him (Kebe) day by day.
"We can't take a chance on him with a thigh injury. If he's not right Friday we'll work on him again for Tuesday."
On Leigertwood, McDermott added: "We're hopeful he should be okay and everyone else is fine as well."
Goalkeeper Tom Heaton is one of two Cardiff players who will be assessed ahead of the game, although manager Dave Jones is keeping his cards close to his chest regarding the identity of the other.
Heaton is battling to overcome a groin strain in order to take part at the Madejski Stadium, although he found himself on the bench on the final day of the regular season against Burnley after two games as number one.
On-loan Derby stopper Stephen Bywater had provided strong competition over the run-in and should Heaton be available, it remains to be seen who will get the nod.
Influential centre-back Mark Hudson is not believed to be the other player despite being replaced just 30 minutes into his return to City's starting XI at Turf Moor after injury, with Jones insisting the move was tactical.
Otherwise, the Bluebirds boss just has the task of deciding which line-up to go with after City flattered to deceive over the final two games of the campaign.
Striker Michael Chopra and midfielders Jay Emmanuel-Thomas and Stephen McPhail are leading contenders for possible recalls.