|Venue: Twickenham Stoop Date: Sunday, 4 April Kick-off: 20:00 BST Coverage: Live commentary on BBC local radio and score updates on the BBC Sport website.|
Harlequins welcome back a host of players from injury and international duty for their European Challenge Cup last 16 tie against Ulster.
Scotland pair James Lang and Scott Steele return, while Nathan Earle and Paul Lasike are among a quintet back from injury lay-offs.
Jordi Murphy captains Ulster, with Ireland lock Iain Henderson ruled out.
Billy Burns comes back into the side at fly-half, meaning Michael Lowry is shifted to full-back.
Robert Baloucoune and Jacob Stockdale are named on the wings, with Stuart McCloskey and James Hume continuing their midfield partnership.
With Marcell Coetzee ruled out with a hamstring injury, Nick Timoney gets the nod at number eight where he will join Murphy and Sean Reidy at the back of the scrum.
Both sides have dropped from the European Champions Cup into the second-tier competition.
This will be Ulster’s first ever game in the European Challenge Cup, and the Irish side have won five of their previous seven meetings with Quins in European games.
Harlequins: Green; Northmore, Lang, Lasike, Earle; Herron, Steele; Garcia Botta, Elia, Collier, Tizard, Hammond, White, Kenningham, Lawday (capt).
Replacements: Head, Els, Kerrod, Cavubati, Jurevicius, Stafford, Tapuai, R Chisholm.
Ulster: Lowry; Baloucoune, Hume, McCloskey, Stockdale; Burns, Cooney; O’Sullivan, Herring, Moore, O’Connor, Treadwell, Reidy, Murphy (capt), Timoney.
Replacements: Andrew, Warwick, O’Toole, Izuchukwu, Rea, Mathewson, Madigan, McIlroy.
Referee: Romain Poite (France).