Harlequins winger Ugo Monye will make his 200th appearance for the club when they take on Connacht at The Stoop in the Heineken Cup.
Monye, who was one of nine Harlequins players named in the England Elite Squads earlier this week, returns on the left wing and is one of seven changes to the team that defeated London Welsh last weekend.
Mike Brown starts at full-back with Matt Hopper and Tom Casson returning to partner in the centres.
Olly Kohn is named in the second row, while Maurie Fa'asavalu joins Nick Easter and captain, Chris Robshaw in the back row.
Following their involvement against London Welsh, Charlie Matthews, Tom Guest and George Lowe are named among the replacements.
Harlequins are one of three teams, along with French sides Toulon and ASM Clermont Auvergne, who are still unbeaten in this season's Pool stages and have won all four of their games so far.
Meanwhile, Connacht head coach Eric Elwood has made three personnel changes to the team that beat Dragons last Saturday evening.
The back row has been boosted with the return from injury of flanker Johnny O'Connor, who missed out on last weekend's clash.
O'Connor starts at Openside while Eoin McKeon, who this week signed a two year extended contract with the province, moves to number eight, replacing the injured George Naoupu.
In the back line, Tiernan O'Halloran starts on the right wing while Fetu'u Vainikolo is named at number 11.
Matthew Jarvis replaces Dan Parks at out-half in what will be his third Heineken Cup game. The 22 year old came off the bench in the back-to-back fixtures against French side Biarritz.
Miah Nikora, who returned to training last week following injury, is named on the bench along with replacement winger James Loxton, who could earn his first Heineken Cup appearance on Saturday afternoon.
Connacht have proved tough opposition for Harlequins in this tournament, winning one clash and narrowly missing out on bonus points with eight-point defeats in the other two.
Harlequins are aiming for the fifth consecutive victory in the Heineken Cup, their current run of four is their best winning sequence to date. Dan Parks is two points away from hitting 50 points for Connacht in the tournament this season.
Harlequins: 15 Mike Brown, 14 Tom Williams, 13 Matt Hopper, 12 Tom Casson, 11 Ugo Monye, 10 Nick Evans, 9 Danny Care, 8 Nick Easter, 7 Chris Robshaw (c), 6 Maurie Fa'asavalu, 5 George Robson, 4 Olly Kohn, 3 James Johnston, 2 Joe Gray, 1 Joe Marler.
Replacements: 16 Rob Buchanan, 17 Mark Lambert, 18 Will Collier, 19 Charlie Matthews, 20 Tom Guest, 21 Karl Dickson, 22 Ben Botica, 23 George Lowe.
Connacht: 15 Robbie Henshaw, 14 Tiernan O'Halloran, 13 Eoin Griffin, 12 Dave McSharry, 11 Fetu'u Vainikolo, 10 Matthew Jarvis, 9 Kieran Marmion, 8 Eoin McKeon, 7 Johnny O'Connor, 6 Andrew Browne, 5 Mike McCarthy, 4 Michael Swift, 3 Nathan White (capt), 2 Jason Harris-Wright, 1 Denis Buckley.
Replacements: 16 Ethienne Reynecke, 17 Brett Wilkinson, 18 Ronan Loughney, 19 Mick Kearney, 20 Eoghan Grace, 21 Paul O'Donohoe, 22 Miah Nikora, 23 James Loxton.
Date: Saturday, January 12
Venue: Twickenham Stoop
Kick-off: 13.35 GMT
Referee: Neil Paterson (Scotland)