England have named Ben Morgan at number eight for Sunday's pivotal RBS 6 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."
Lancaster views Morgan as a "dead-set, like-for-like replacement" for Vunipola due to his ability to get England over the gain line, although doubts persist over his capacity to last 80 minutes.
Explosive centre Manu Tuilagi recovered from a torn pectoral muscle to play for Leicester last weekend, but his lack of match fitness after six months on the sidelines meant he was not considered for selection.
In total there are six survivors from the starting XV that was overwhelmed 30-3 in Cardiff last year, denying England the Grand Slam at the final hurdle.
The crushing nature of that result has haunted the squad ever since and despite going on to deliver notable victories over Australia, Argentina and Ireland, they are desperate to complete a first win in the fixture under Lancaster in three attempts.
Wales are targeting an unprecedented third successive Six Nations crown - an achievement that has never been managed outright before - and a fourth consecutive victory over England.
Sunday's winners will go on to contest the title on the final weekend, with England travelling to Rome to face Italy, while the losers will be removed from contention.
Adding further significance to the match is that it will be the final time Wales visit Twickenham before the rivals meet at the same venue in the pool stages of the 2015 World Cup.
"We can't wait to play at home again," Lancaster said.
"The players have said that the atmosphere at Twickenham for the Ireland game was the best they had experienced and I'm sure it will be the same again on Sunday.
"It definitely gives us an extra lift and that's what we want against another experienced, high-quality side, who are looking to defend their title."