Connacht boss Pat Lam has made four personnel changes for his side's Heineken Cup clash with Saracens on Saturday at Allianz Park.
Dan Parks has been named in the number 10 jersey. The veteran fly-half is 27 points shy of reaching the milestone of 500 Heineken Cup points. Mayo-born Gavin Duffy also returns to the back line this week, starting at full-back.
The second-row partnership of Connacht's highest capped player Michael Swift and captain Craig Clarke returns this week to boost the pack.
There is a reshuffle in the back row with John Muldoon moving to number eight in place of the injured Eoin McKeon. Andrew Brown slots in to blindside flanker while Jake Heenan remains on the openside.
Galway-born back Tiernan O'Halloran is named on the replacements bench.
"This is a huge game for Connacht, we all know that," added Lam.
"Win and we qualify for a quarter final in Europe. Big games require your big players to step up and lead the way, so it's great to be able to call on four of our most experienced players Gavin, Dan, Swifty and Craig this week.
"We were unfortunate to lose Eoin McKeon to injury in training this week. He has had to have surgery on his hand and is likely to be out of action for up to two months. It's a big loss to our back row resources.
"We have a lot of respect for what Saracens are achieving. They are well coached, well resourced and top of the English premiership, with an excellent stadium. They have only lost once on this new 4G surface and they have racked up a high number of points against opposition teams. If we play as individuals, it will be a long day at the office tomorrow."
Meanwhile, in the Saracens backs, Charlie Hodgson replaces Owen Farrell at fly-half, and is partnered by Richard Wigglesworth at scrum-half. Scotland international centre Duncan Taylor comes into the midfield, as Chris Wyles is named among the replacements.
In the pack, Matt Stevens returns to the front row starting at tighthead prop, and in the second-row, England Saxon lock forward George Kruis partners captain Steve Borthwick.
Saracens: '5 Alex Goode, 14 Chris Ashton, 13 Duncan Taylor, 12 Brad Barritt, 11 David Strettle, 10 Charlie Hodgson, 9 Richard Wigglesworth, 8 Ernst Joubert, 7 Kelly Brown, 6 Billy Vunipola, 5 George Kruis, 4 Steve Borthwick (c), 3 Matt Stevens, 2 Schalk Brits, 1 Mako Vunipola
Replacements: 16 Jamie George, 17 Richard Barrington, 18 James Johnston, 19 Alistair Hargreaves, 20 Jackson Wray, 21 Neil de Kock, 22 Owen Farrell, 23 Chris Wyles
Connacht: 15 Gavin Duffy, 14 Fionn Carr, 13 Robbie Henshaw, 12 Eoin Griffin, 11 Matt Healy, 10 Dan Parks, 9 Kieran Marmion, 8 John Muldoon, 7 Jake Heenan, 6 Andrew Browne, 5 Craig Clarke (c), 4 Michael Swift, 3 Nathan White, 2 Sean Henry, 1 Brett Wilkinson
Replacements: 16 Jason Harris-Wright, 17 Denis Buckley, 18 Rodney Ah You, 19 Mick Kearney, 20 George Naoupu, 21 Paul O'Donohoe, 22 Darragh Leader, 23 Tiernan O'Halloran
Date: Saturday, January 18
Kick-off: 13:35 GMT
Venue: Allianz Park
Referee: Leighton Hodges (Wales)
Assistant referees: Gwyn Morris (Wales), Greg Morgan (Wales)
Television match official: Gareth Simmonds (Wales)