Karacan, Ake, Cooper and Blackman inJem Karacan, Nathan Ake, Jake Cooper and Nick Blackman all come into the side for tonight's game with Brimingham City at Madejski Stadium, as Steve Clarke makes four changes.
Club captain Karacan began Saturday's FA Cup Semi-Final with Arsenal on the substitutes bench but has started the Royals' previous two league outings.
Academy graduate Cooper replaces fellow academy graduate Alex Pearce in the heart of defence, while Chelsea loanee Nathan Ake makes his return to the side after missing Saturday's game due to being cup tied.
Blackman also makes his return to action following injury and, elsewhere, academy duo Jack Stacey and Andrija Novakovich are both handed places on the substitute's bench.
Reading: Federici, Gunter, Obita, Hector, Cooper, Chalobah, Karacan (c), Ake, McCleary, Mackie, Blackman.
Subs: Andersen, Kelly, Akpan, Norwood, Stacey, Appiah, Novakovich.
Birmingham City: Randolph, Spector, Morrison, Kiernan, Caddis, Tesche, Gleeson, Grounds, Fabbrini, Donaldson, Thomas.
Subs: Doyle, Cotterill, Novak, Shinnie, Gray, Davis, Dyer.