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