The 19 year old midfielder has been on loan at Southend United this season and has scored three goals in twelve plus one sub appearances. He has been booked on four occasions.
Although the Leytonstone born player has not made a first team appearance for Chelsea, he has trained with the first team squad.
Sawyer scored for Chelsea Reserves last week in a 3-0 friendly win against QPR Reserves who included former Sky Blue Gary Borrowdale and is expected to be included in the City squad to face Cardiff City on Wednesday night.
He and has played against City at U18's level and his loan at the Ricoh Arena is only for Championship matches and not for City's FA Cup games.