England have named Ben Morgan at number eight for Sunday's potentially crucial Six Nations title showdown with Wales at Twickenham.
Morgan has been promoted to the starting XV in place of Billy Vunipola, who has been ruled out of the final two rounds of the championship with a sprained ankle.
The Gloucester back row has made a substantial contribution to England's Six Nations campaign as an impact replacement, but is to win his 19th cap as a starter against Warren Gatland's champions.
Filling Morgan's place on the bench is Tom Johnson of Exeter in the second and final change to the 23 that dispatched Ireland 13-10 two weeks ago.
"Ben has made an impact off the bench in the previous games," England head coach Stuart Lancaster said.
"He has been pushing hard for the number eight shirt and now gets his opportunity, so we are looking forward to seeing him from the start.
"Tom has been outstanding for Exeter and gives us options off the bench as he has played in all three back-row positions for his club."
England: 15 M Brown (Harlequins); 14 J Nowell (Exeter), 13 L Burrell (Northampton), 12 B Twelvetrees (Gloucester), 11 J May (Gloucester); 10 O Farrell (Saracens), 9 D Care (Harlequins); 1 J Marler (Harlequins), 2 D Hartley (Northampton), 3 D Wilson (Bath), 4 J Launchbury (Wasps), 5 C Lawes (Northampton), 6 T Wood (Northampton), 7 C Robshaw (Harlequins, capt), 8 B Morgan (Gloucester).
Replacements: 16 T Youngs (Leicester), 17 M Vunipola (Saracens), 18 H Thomas (Sale), 19 D Attwood (Bath), 20 T Johnson (Exeter), 21 L Dickson (Northampton), 22 G Ford (Bath), 23 A Goode (Saracens).