Lewis Ludlam is now certain to make his England debut on Sunday after being promoted from the bench for the World Cup warm-up match against Wales at Twickenham (kick-off 2pm).
Ludlam comes in for Bath flanker Sam Underhill, who has suffered a toe injury.
Saints will have three players in the England squad, with Piers Francis starting at inside centre and Courtney Lawes now on the bench following Underhill's withdrawal.
There will be four Northampton players involved overall as Dan Biggar is on the Wales bench.
But the day is all about indefatigable back row forward Ludlam, who has been rewarded for a stellar 2018/19 season at Saints.
The 23-year-old was one of his club's stand-out players as they finished fourth in the Gallagher Premiership, reached the European Challenge Cup quarter-finals and won the Premiership Rugby Cup.
Ludlam made 27 appearances in total, starting in 24 of those, scoring four tries in the process.
And he will now look to impress on the big stage as he bids to book his ticket to Japan, where the World Cup will be held from September.
England starting XV
15 Elliot Daly (Saracens, 30 caps)
14 Joe Cokanasiga (Bath Rugby, 4 caps)
13 Jonathan Joseph (Bath Rugby, 40 caps)
12 Piers Francis (Saints, 4 caps)
11 Anthony Watson (Bath Rugby, 33 caps)
10 George Ford (Leicester Tigers, 55 caps) C
9 Willi Heinz (Gloucester Rugby, uncapped) VC
1 Ellis Genge (Leicester Tigers, 9 caps)
2 Luke Cowan-Dickie (Exeter Chiefs, 11 caps)
3 Dan Cole (Leicester Tigers, 85 caps)
4 Joe Launchbury (Wasps, 58 caps)
5 Charlie Ewels (Bath Rugby, 10 caps)
6 Lewis Ludlam (Saints, uncapped)
7 Tom Curry (Sale Sharks, 10 caps)
8 Billy Vunipola (Saracens, 41 caps)
16 Jack Singleton (Saracens, uncapped)
17 Joe Marler (Harlequins, 59 caps)
18 Harry Williams (Exeter Chiefs, 17 caps)
19 George Kruis (Saracens, 32 caps)
20 Courtney Lawes (Saints, 71 caps)
21 Ben Youngs (Leicester Tigers, 85 caps)
22 Joe Marchant (Harlequins, uncapped)
23 Manu Tuilagi (Leicester Tigers, 32 caps)
Wales: Smith, Owens, Francis; Beard, AW Jones (c); Wainwright, Tipuric, Moriarty; G Davies, Anscombe; Adams, Parkes, J Davies, North, L Williams.
Replacements: Dee, W Jones, Lewis, Ball, Shingler, A Davies, Biggar, Watkin.