A scan on Monday confirmed the worst after Whittingham was subbed during Saturday's 2 - 1 win over Crystal Palace.
City are already without Joe Ledley (broken and dislocated finger), Ross McCormack (Hamstring), Jay Bothroyd (Hamstring) and long term injured Riccy Scimeca and Tony Capaldi.
Paul Parry and Miguel Comminges are likely to come into the starting line up to replace Ledley and Whittingham.
If no senior players are fit then Dave Jones will have to bring another youngster onto the bench to join Jon Brown and Darcy Blake. Unless he can get someone else on loan.