The injury to Sowden-Taylor was one of three serious accidents in Welsh rugby on 13 September.

BBC: Sowden-Taylor grimaces as his ankle is caught beneath him

It is the first time Ulster have reached the final of Europe's biggest rugby competition since they won it 13 years ago.

BBC: Thousands celebrate Ulster rugby triumph

However, should he be voted off on the weekends of either 4-5 or 11-12 December, Saracens could re-introduce Henson to rugby when their A team face Harlequins on 13 December.

BBC: Gavin Henson can make 2013 Lions tour - Andy Irvine

Like former team-mate Lee Smith, Hall has been tipped for a switch to rugby union but sees his immediate future in the 13-man game.

BBC: Ryan Hall signs new contract with Leeds Rhinos

The Premiership outfit, however, will have to be granted special dispensation for the tie to be played at their 13, 591-capacity Franklin's Gardens as European Rugby Cup regulations stipulate that knock-out stage venues must be able to accommodate a crowd of at least 15, 000.

BBC: Castres 12-23 Northampton

Welsh rugby's latest row erupted when Wales coach Warren Gatland wanted his Grand Slam winners for 13 days to prepare for playing world champions South Africa in Cardiff on 8 November.

BBC: Lewis remains positive after row