The 18-year-old can play at both centre-back and left-back, but comes in to fill the space left by the absence of Gael Clichy and Aleksandar Kolarov on the flank
Elsewhere for the Premier League champions, Samir Nasri is the only other change with Gareth Barry coming into midfield. Kolo Toure partners Matija Nastasic at centre-back, while their midfield consists of Javi Garcia, Barry, Yaya Toure and David Silva.
Up front, Carlos Tevez and Sergio Aguero continue, with Edin Dzeko on the bench alongside club captain Vincent Kompany and Scott Sinclair.
For the visitors, Pavel Pogrebnyak starts up front, with a midfield five consisting of Jimmy Kebe, Mikele Leigertwood, Jem Karacan, Jay Tabb and Jobi McAnuff attempting to stifle their opponents.
Manchester City XI: Hart; Zabaleta, Kolo Toure, Nastasic, Rekik; Garcia, Barry, Silva, Yaya Toure; Aguero, Tevez.
Subs: Wright, Kompany, Razak, Milner, Lescott, Sinclair, Dzeko.
Reading XI: Federici; Gunter, Mariappa, Pearce, Harte; Kebe, Leigertwood, Karacan, Tabb, McAnuff; Pogrebnyak.
Subs: Taylor, Shorey, Gorkss, Guthrie, Robson-Kanu, Le Fondre, Hunt.