Stephen Ferris, who featured for Ulster in the 2012 Heineken Cup final, is currently on the comeback trail following a long-term ankle injury.

The 28-year-old will be in contention for a starting place when this season's number 1 seeds take on Saracens in the quarter-final at Ravenhilll on Saturday, 5 April.

Like Ferris, Saracens and England Saxons back rower Will Fraser has been out of action with a leg injury, while Gonalo Camacho, who scored the winning try in the 2011 Amlin Challenge Cup final, and Elvis Vermeulen, who has made 46 Heineken Cup appearances for Clermont, return to their clubs' squads.

Under ERC tournament rules, teams who have qualified for the knockout stages of the Heineken Cup can nominate up to three players for registration to supplement their initial 38-player European squads.

The registrations of players who were nominated by Thursday, March 20 are subject to confirmation by the relevant Unions and by ERC.

The following have been nominated by their teams as registered players for the knockout stages of the 2013/14 Heineken Cup:

CLERMONT AUVERGNE

Additional player: Etienne FALGOUX
Date of Birth: 19/1/1993
Position: Prop

Additional player: Uwanakaro TAWALO
Date of Birth: 27/2/1992
Position: Full-back/winger

Additional player: Elvis VERMEULEN
Date of Birth: 5/4/1979
Position: Back rower

LEICESTER TIGERS

Additional player: Gonzalo CAMACHO
Date of Birth: 28/8/1984
Position: Winger

Additional player: Pablo MATERA
Date of Birth: 18/7/1993
Position: Back rower

Additional player: Logovii MULIPOLA
Date of Birth: 11/3/1987
Position: Prop

LEINSTER

Additional player: Darragh FANNING
Date of Birth: 9/2/1987
Position: Winger

Additional player: Luke McGRATH
Date of Birth: 3/2/1993
Position: Scrum half

MUNSTER

Additional player: Gerry HURLEY
Date of Birth: 16/5/1984
Position: Scrum half

Additional player: Quentin MacDONALD
Date of Birth: 25/9/1988
Position: Hooker

Additional player: Gerard VAN DEN HEEVER
Date of Birth: 13/4/1989
Position: Winger

SARACENS

Additional player: Will FRASER
Date of Birth: 29/10/1989
Position: Back rower

Additional player: Tim STREATHER
Date of Birth: 14/6/1988
Position: Centre

TOULON

Additional player: Alexandre MENINI
Date of Birth: 5/8/1983
Position: Prop

Additional player: Ivan ROUX
Date of Birth: 15/6/1994
Position: Centre

TOULOUSE

Additional player: Francois CROS
Date of Birth: 25/3/1994
Position: Back rower

ULSTER

Additional player: Stephen FERRIS
Date of Birth: 2/8/1985
Position: Back rower

Additional player: Stuart McCLOSKEY
Date of Birth: 6/8/1992
Position: Centre

Additional player: Andrew WARWICK
Date of Birth: 12/3/1991
Position: Prop