Wallace is awaiting the results of an MRI scan with Niall O’Connor set to come in at fly-half.

Clinton Schifcofske and Carlo del Fava are also included in the 24-man party but remain doubtful.

David Pollock is absent with a shoulder injury but Paul Steinmetz and Chris Henry come into Matt Williams' panel.

Schifcofske is trying to overcome an ankle problem while del Fava suffered a 'stinger' in the Magners League defeat by Llanelli Scarlets at Ravenhill.

Stephen Ferris is not yet considered fit enough to take his place in the panel but Thomas Anderson is again in the frame after coming off the replacements' bench last Friday.

Ulster are looking for their first victory of the season after losing their opening two league games to the Scarlets and the Blues.

The Dragons have lost their three opening games and are seeking a first win on the road since a victory at Glasgow in January.

Coach Paul Turner has never led them to a win in Ravenhill, their only victory at the ground coming in October 2004.

Marc Stcherbina, Andy Williams and Andy Hall have joined Martyn Thomas and Kevin Morgan on the Welsh region's injury list.

Rhys Thomas, Adam Jones and Ashley Smith are also doubts, while Jason Tovey could come in at full-back.