James O'Connor will make his London Irish debut this Sunday when Northampton Saints visit the Madejski Stadium.
O'Connor will line up at full back in a back three along with Topsy Ojo and Sailosi Tagicakibau. Fergus Mulchrone and Eamonn Sheridan continue their centre partnership.
Ian Humphreys and Tomás O'Leary will play together in the halves. O'Leary will captain the side in the absence of George Skivington.
John Yapp, David Paice and Leo Halavatau will start in the front row with Ian Gough and Bryn Evans in the second row. Chris Hala'ufia will play alongside Samoa International Ofisa Treviranus and Blair Cowan in the back row.
"The team is looking forward to the contest on Sunday. We felt we let a golden opportunity to win a valuable Premiership match slip last weekend and want to put in a big performance in front of our home supporters," said Exiles boss Brian Smith.
"Northampton are the in-form team at the moment and we will have to be at our best to shut them down. It's been a big week for the club with the announcement of James O'Connor and we hope we see a big turn out by our supporters on Sunday to welcome him to the club."
Meanwhile, Saints head to Reading to face an Exiles team which has lost just the one Aviva Premiership match at the Madesjki Stadium in 2013.
Director of rugby Jim Mallinder and the Saints coaches have made two changes to the starting line-up from last Saturday.
Ben Foden's inclusion on the England bench for Saturday's match against Australia means that James Wilson wears the 15 shirt, with Tom Collins coming in for the injured Jamie Elliott.
Tom Mercey has recovered from his recent spell on the sidelines to come onto the replacements' bench, with a first call-up to the senior match day squad for Kiwi fly half and centre Glenn Dickson.
Form: London Irish's three game winning run in all tournaments came to an end late in their encounter with the Falcons at Newcastle on Sunday. The Exiles have been defeated only once at Madejski Stadium in Aviva Premiership Rugby in 2013: 23-29 to Exeter in September. Northampton Saints were impressive in beating top of the table Saracens 41-20 at Franklin's Gardens on Saturday and have now handed Saracens their two biggest Premiership defeats since 2009. The Saints only away victory so far this season came at Harlequins on 13th September. Both encounters between the two clubs in the Premiership last season ended in easy victories for the home side, although Northampton have still been victorious on three of their last four visits to Reading in the Premiership.
London Irish: 15 James O'Connor, 14 Topsy Ojo, 13 Fergus Mulchrone, 12 Eamonn Sheridan, 11 Sailosi Tagicakibau, 10 Ian Humphreys, 9 Tomás O'Leary (c), 8 Chris Hala'ufia 7 Ofisa Treviranus, 6 Blair Cowan, 5 Bryn Evans, 4 Ian Gough, 3 Leo Halavatau, 2 David Paice, 1 John Yapp.
Replacements: 16 Mike Mayhew, 17 Matt Parr, 18 Jamie Hagan, 19 Kieran Low, 20 Declan Danaher, 21 Alex Lewington, 22 Shane Geraghty, 23 Darren Allinson
Northampton Saints: 15 James Wilson, 14 Ken Pisi, 13 George Pisi, 12 Luther Burrell, 11 Tom Collins, 10 Stephen Myler, 9 Kahn Fotuali'i, 8 Sam Dickinson, 7 Phil Dowson (c), 6 Calum Clark, 5 Christian Day, 4 Samu Manoa, 3 Salesi Ma'afu, 2 Mike Haywood, 1 Alex Waller.
Replacements: 16 Ross McMillan, 17 Ethan Waller, 18 Tom Mercey, 19 GJ van Velze, 20 Ben Nutley, 21 Ryan Glynn, 22 Glenn Dickson, 23 Dom Waldouck.
Date: Sunday, November 3
Venue: Madejski Stadium
Referee: Andrew Small
Assistant referees: Roger Baileff and Stuart Terheege
TMO: Ashley Rowden