England and Ireland have named near full-strength sides for Saturday's World Cup warm-up match at Twickenham.
Manu Tuilagi starts at outside centre for the hosts while Ireland have made 12 changes to the experimental side that cruised past Italy.
England lost in Cardiff last weekend as Wales moved to number one in the world, but a win for Ireland will move them ahead of the Welsh in the rankings.
Ireland last won at Twickenham in 2018 when they claimed the Grand Slam.
'He's in the best physical shape'
England scrum-half Ben Youngs says Tuilagi is in the shape of his life as the 2003 World Cup winners look to release the powerful outside centre in midfield.
Tuilagi will be making his first start of the World Cup warm-up Tests having impressed off the bench in both matches against Wales.
"He's probably in the best physical shape I've ever seen him," said Youngs of his Leicester Tigers team-mate.
"We saw glimpses of it in the first two games, particularly the first Wales game with his carry, so we'll try to get him into the game early against Ireland."
Inside Tuilagi, England head coach Eddie Jones has named George Ford and Owen Farrell in the same starting side for the first time in more than a year.
Farrell will partner Tuilagi in the centre at Twickenham - something he has never done before from the start of a Test match - as Ford retains his place at fly-half.
Selecting both playmakers served England well in the early stages of Jones' era, but when the heavy duty ball-carrying options of Manu Tuilagi and Ben Te'o became available, the Australian coach changed emphasis.
Elsewhere, Jones has labelled the back row pair Tom Curry and Sam Underhill England's 'Kamikaze kids' because "they hit everything that moves".
"There's no ceiling for them," said Jones.
"Playing two guys who are pretty good at the breakdown might give us an advantage in that area."
Ireland chase top spot without their talisman
Ireland can become the best side in the world for the first time with victory, but they will have to do it without first and second-choice fly-halves Johnny Sexton and Joey Carbery.
Carbery's involvement at the World Cup is threatened by an ankle injury, offering Ross Byrne the chance to cement his place as Sexton's understudy at fly-half.
The 24-year-old from Leinster, who has won two caps, will make his full Test debut with Ireland not risking Sexton after Carbery's set-back.
And Ireland head coach Joe Schmidt says he has confidence the rookie will seize his opportunity.
"Ross has trained really well and it's not his debut, he's had time with us before," he said.
Apart from the selection of Byrne, Schmidt's selection has a much more familiar look about it after an experimental line-up secured victory over the Italians at Aviva Stadium on 10 August.
Rob Kearney, Jacob Stockdale, Bundee Aki, Conor Murray, Cian Healy, captain Rory Best, Tadhg Furlong, Iain Henderson, Peter O'Mahony, Josh van der Flier and CJ Stander are among a number of frontline players to make their seasonal bows.
After Saturday's game at Twickenham, Ireland continue their World Cup preparation games by facing Wales in Cardiff on 31 August and Warren Gatland's side again in Dublin on 7 September.
Teams
England: Daly; Cokanasiga, Tuilagi, Farrell, May; Ford, Youngs; Marler, George, Sinckler, Itoje, Kruis, Curry, Underhill, B Vunipola.
Replacements: Cowan-Dickie, M Vunipola, Cole, Lawes, Wilson, Heinz, Francis, Joseph.
Ireland: R Kearney; Larmour, Ringrose, Aki, Stockdale; R Byrne, Murray; Healy, Best, Furlong, Henderson, Kleyn; O'Mahony, Van der Flier, Stander.
Replacements: Cronin, J McGrath, Porter, Toner, Beirne, L McGrath, Carty, Conway.