Marcell Coetzee ruled out of Ulster's Challenge Cup clash with Harlequins

Ulster's powerful backrower Marcel Coetzee has been ruled out of the province's Challenge Cup meeting with Harlequins on Sunday. Coetzee has been struggling with a hamstring injury sustained in the March 6 Pro14 defeat to Leinster, and Ulster have now confirmed he will not be fit for Sunday's game at Twickenham Stoop.

Coetzee, who will join South African side the Bulls this summer, is set to be out of action 'for a number of weeks.'

Ulster could also be without Billy Burns for the trip to London.

The out-half is recovering from a groin injury sustained ahead of Ireland's Six Nations win against England, and will be monitored throughout the week before a decision is made on his fitness.

David O’Connor will not be available for selection, having recently undergone shoulder surgery.

Meanwhile, Zebre's Marco Manfredi has been banned for three weeks following his red card against Ulster on March 19.

The hooker was shown a red card by Andrew Brace in the 34th minute of the 49-3 defeat after his elbow collided with John Cooney's face.