Cox returns from suspension in place of Henri Lansbury, who drops to the bench after making his full debut in the midweek draw with Blackburn Rovers.
Jermaine Jenas is once again named as a sub as he continues a loan spell at the City Ground.
Zakauni makes the bench for the first time this season, with in-form striker Emile Sinclair leading the line for Posh.
Forest: Camp, Halford, Ayala, Collins, Harding, Gillett, Cohen, McGugan, Reid, Cox, Sharp
Peterborough: Olejnik, Alcock, Brisley, Bostwick, Barnett, Boyd, Sinclair, Rowe, Ferdinand, Little, Knight-Percival