Midfielder Denilson (back) is also struggling for fitness, but Czech winger Tomas Rosicky (hamstring) could return.
Arsene Wenger claimed Rosicky would either be fit to play at Fratton Park or in Sunday’s FA Cup tie at West Ham, but revealed Nicklas Bendtner (groin) was still three weeks away from a comeback.
Alex Song is available as he will not join up with Cameroon at the African Nations Cup until January 4, but Emmanuel Eboue is already away with the Ivory Coast.
Gael Clichy (back), Kieran Gibbs (foot), Robin van Persie (ankle) and Johan Djourou (knee) remain sidelined.
Arsenal (from): Almunia, Traore, Vermaelen, Gallas, Sagna, Nasri, Diaby, Song, Rosicky, Walcott, Arshavin, Fabianski, Ramsey, Eduardo, Silvestre, Vela, Merida, Senderos, Denilson, Fabregas.