Rojo, whose last game was at the World Cup, has been absent with an unspecified injury all season but did recently feature for the Under 23s as he works his way back to fitness.
Romero, meanwhile, serves a one-match ban for picking up a red card in the defeat to Derby County, his first game since April.
Here is the squad which will travel down to East London for the meeting with Manuel Pellegrini’s team. Antonio Valencia, Diogo Dalot, Phil Jones, Jesse Lingard and Andreas Pereira have all been left out.
David de Gea, Lee Grant; Chris Smalling, Victor Lindelof, Eric Bailly, Luke Shaw, Ashley Young, Matteo Darmian; Marouane Fellaini, Fred, Nemanja Matic, Paul Pogba, Juan Mata, Ander Herrera, Scott McTominay; Marcus Rashford, Alexis Sanchez, Anthony Martial, Romelu Lukaku.