Harlequins welcome back Mike Brown, Danny Care and Chris Robshaw to the starting line-up after international duty with England.
In the backs, Ollie Lindsay-Hague and Sam Smith start on the wings, with Matt Hopper and Jordan Turner-Hall named in the centres.
Nick Evans continues at fly-half and partners Care in the half-backs.
In the forwards, Dave Ward starts at hooker, while Luke Wallace switches to the blindside as captain Robshaw is named at openside flanker.
Among the replacements, Max Crumpton will look to make his first senior appearance for the Club.
Meanwhile, London Irish scrum-half Tomás O'Leary has returned to the starting XV for Saturday's small trip across London.
The Irishman returns to partner Shane Geraghty at half-back and Jimmy Stevens starts in the front row in place of David Paice.
Matt Parr, Jimmy Stevens and Jamie Hagan make up the front row with George Skivington and Nic Rouse in the second row. Kieran Low and Blair Cowan will play alongside Ofisa Treviranus in the back row.
Eamonn Sheridan and Fergus Mulchrone are in the centres with Marland Yarde, Topsy Ojo and James O'Connor making up the back three.
"I'd like to thank our supporters for giving Declan Danaher a wonderful send off last Saturday and encourage them to support the team this weekend at the Stoop," said London Irish director of rugby Brian Smith.
"Harlequins are a very good team and we are looking forward to the contest tomorrow."
Two players will play against their future clubs, with Marland Yarde having signed for Harlequins and Tom Guest heading the other way next season.
Form: Harlequins last eight matches in Aviva Premiership Rugby have all been won by the home side on the day. 'Quins have won their last six home Premriship games since losing 12-22 to Saracens in Round Four. London Irish have slipped to three straight defeats since beating Wasps at Adams Park on 15 February. The Exiles have won three of their last five away games in all tournaments. London Irish were victorious 18-13 against 'Quins in Reading in Round Five, to end a five game losing streak to their once close neighbour, and have not achieved a season's double over Harlequins since 2004/05. Andrew Small is taking charge of this match, and the away side has won the last seven times he has refereed in the Premiership.
Harlequins: 15 Mike Brown, 14 Ollie Lindsay-Hague, 13 Matt Hopper, 12 Jordan Turner-Hall, 11 Sam Smith, 10 Nick Evans, 9 Danny Care, 8 Nick Easter, 7 Chris Robshaw (c), 6 Luke Wallace, 5 George Robson, 4 Nick Kennedy, 3 Kyle Sinckler, 2 Dave Ward, 1 Joe Marler
Replacements: 16 Max Crumpton, 17 Mark Lambert, 18 Paul Doran Jones, 19 Charlie Matthews, 20 Tom Guest, 21 Karl Dickson, 22 Ben Botica, 23 Tim Molenaar
London Irish: 15 James O'Connor, 14 Topsy Ojo, 13 Fergus Mulchrone, 12 Eamonn Sheridan, 11 Marland Yarde, 10 Shane Geraghty, 9 Tomás O'Leary, 8 Ofisa Treviranus, 7 Blair Cowan, 6 Kieran Low, 5 Nic Rouse, 4 George Skivington (c), 3 Jamie Hagan, 2 Jimmy Stevens, 1 Matt Parr
Replacements: 16 Mike Mayhew, 17 John Yapp, 18 Leo Halavatau, 19 Jebb Sinclair, 20 Gerard Ellis, 21 Alex Lewington, 22 Myles Dorrian, 23 Darren Allinson
Date: Saturday, March 29
Kick-off: 15:00 GMT
Venue: Twickenham Stoop
Referee: Andrew Small
Assistant referees: Gareth Copsey, Andy Watson
Television match official: Keith LewisLewis