The home side have made four changes to the side that beat Worcester Warriors a fortnight ago, but Chris Robshaw misses out with an ankle injury.
Both sides have already qualified for the playoffs, but a big victory would give the winner a chance to move above second-placed Leicester Tigers, securing a home fixture in the semi-finals.
Harlequins: Brown, Williams, Lowe, Casson, Monye, Evans, Care, Easter, Wallace, Guest, Robson, Kohn, Johnston, Buchanan, Marler
Northampton Foden, K Pisi, G Pisi, Burrell, Elliott, Myler, Dickson, Manoa, Wood, Clark, Day, Lawes, Mujati, Hartley, Tonga'uiha
Sports Mole says: Northampton to clinch a close game