.... to assess the full extent of his knee injury.
The 20-year-old Frenchman could be another major problem to Glenn Roeder who (if the player is out for weeks as expected) would then have 14 players out injured.
Kieron Dyer and Scott Parker both have hopes to play a part in Saturday's hugely important Premiership clash with Watford at St James' Park. Emre could also return.
But on the down side, full-back Celestine Babayaro has a one-match ban after picking up his fifth booking of the season at Stamford Bridge.