England won't be announcing their first XV until 10.25 on Friday morning but head coach Stuart Lancaster has now decided on his matchday squad for what is a must-win game for both teams.
Back row Tom Johnson is the only alteration to the 23 that beat Ireland 13-10 in Round 3, with the Exeter Chiefs flanker replacing the injured Billy Vunipola in the party. Johnson is widely expected to be selected among the replacements for Sunday's game as former Scarlets star Ben Morgan is the overwhelming favourite to take over from the impressive Vunipola at No8.
There is no place in the squad for Lions centre Manu Tuilagi despite the fact that he is now available for selection following a lengthy injury absence and highly-rated wing Marland Yarde will also have to wait for his return to the international fold.
Tuilagi played 69 minutes for Leicester last weekend as he ended a five-and-a-half month spell on the sidelines with a chest injury but Lancaster has opted to keep faith with Luther Burrell after the Northampton midfielder bagged a brace of tries in his first three Test caps.
Yarde played the full 80 minutes for London Irish at Exeter on Saturday as he continued his recovery from a hip problem but Exeter's Jack Nowell and Gloucester's Jonny May are all set to continue out wide as England go in search of a first Triple Crown since 2003.
Tuilagi will continue to train with the squad in the build up to the game, though, as will Wasps prop Matt Mullan.
"The performance against Ireland has given us a lot of confidence going into this game against a high-quality Welsh team and we feel it's right to give the bulk of that 23 another opportunity," said Lancaster.
"Tom Johnson has trained with us throughout and we are looking forward to his contribution. There is a lot of competition for places and to have Marland (Yarde) and Manu (Tuilagi) back training with us this week has been great.
"With Leicester and Wasps not involved in the LV= Cup semi-finals this weekend we are able to keep Matt (Mullan) to provide cover in the front row and also to give Manu more time to get up to speed with the team."
England: David Attwood (Bath Rugby), Dylan Hartley (Northampton Saints), Tom Johnson (Exeter Chiefs), Joe Launchbury (London Wasps), Courtney Lawes (Northampton Saints), Joe Marler (Harlequins), Ben Morgan (Gloucester Rugby), Chris Robshaw (Harlequins), Henry Thomas (Sale Sharks), Mako Vunipola (Saracens), David Wilson (Bath Rugby), Tom Wood (Northampton Saints), Tom Youngs (Leicester Tigers), Mike Brown (Harlequins), Luther Burrell (Northampton Saints), Danny Care (Harlequins), Lee Dickson (Northampton Saints), Owen Farrell (Saracens), George Ford (Bath Rugby), Alex Goode (Saracens), Jonny May (Gloucester Rugby), Jack Nowell (Exeter Chiefs), Billy Twelvetrees (Gloucester Rugby)