Steinmetz being treated for cheek injury by physio Gareth Robinson

Steinmetz picked up the injury in the 27th minute when he attempted to intervene during a bout of fisticuffs.

The former All Black will enter hosital on Monday and a decision will then be made whether to insert a plate.

"We'll have to wait until after surgery on Monday before knowing the extent of the injury," said coach Mark McCall.

Steinmetz, who received a similar injury three seasons ago when he first arrived in the province, could miss the remainder of the season, or just a couple of games.

"Until the prognosis, we will not know the length of time that he will be sidelined," said McCall who believed that he received the blow while attempting to break up a fight.

Steinmetz, however, could only miss one match for Ulster as their only game in the next six weeks in the away trip to Glasgow on 15 April.