Fotheringham suffered the injury in a challenge with Southampton midfielder Andrew Surman after coming on as a second half substitute and helping the Canaries come back from a goal behind against the Saints.
The Scot joins on-loan Chelsea midfielder Jimmy Smith on the sidelines. Smith is expected back sometime in the next month, but it is not yet known how long Fotheringham will be out for.
The spate of injuries, along with the sales of Youssef Safri and Dickson Etuhu, leaves Grant with just Darel Russell and Julien Brellier as specialist central midfielders, although young striker Chris Martin impressed in the role during last night's 4-0 win over Luton reserves.