The in-form midfielder was forced out of the action early in Monday's 2-1 win at Watford with a groin injury.
Speaking after training this afternoon (Thursday, December 31), Mauricio Pochettino told us: "Mousa has a small injury but we hope he's back with the team in a few weeks. He definitely misses Everton. We've no other injuries, everyone is okay."
Clinton Njie (knee) and Alex Pritchard (ankle) remain sidelined.