The Northampton wing will make his first start of England's World Cup warm-up campaign against Ireland on Saturday, while Tuilagi wins his second cap alongside Mike Tindall in a rejigged centre partnership.
The last time they were on a rugby field together, Ashton found himself on the receiving end of an impressive three-punch combination from Leicester's Anglo-Samoan centre.
Tuilagi was later banned for five weeks and missed both the Aviva Premiership final and the Churchill Cup. England, though, always had him in mind for the World Cup.
Ashton emerged with credit from the Welford Road contretemps, not only for the fact he did not hit the deck but for shaking Tuilagi's hand on the final whistle and accepting his apology.
For now, all mention of the episode has been shelved for the good of England. For a squad that revels in often remorseless banter, this subject is off limits.
England need Ashton and Tuilagi - the two players most capable of injecting some spark into their attacking game - in harmony heading into the World Cup.
"I am looking forward to playing alongside him," said Ashton.
"He's quite a player isn't he? The impact he has on games for Leicester - he's the sort of player who can change a game.
"To be outside a guy like that, I'm pretty excited about it.
"He can create the gaps hopefully and I can just be outside. He can definitely change a game and he's got that in him to do that on the weekend.
"We kissed and made up a while ago to be honest. It's all forgotten. We're part of a team now and it's never brought up.
"It might be when we play Leicester v Saints but for the time being it's been put to bed."
Ashton is one of the big jokers in the team - but quite what ardent Northampton supporters will make of him donning a Leicester jersey remains to be seen.
His England team-mates were busy tweeting the snap on their way to Dublin yesterday. Fellow Saint Dylan Hartley joked: "Not sure I can look Chris Ashton in the face anymore. Dirty boy."
But when it comes to his rugby, Ashton is deadly serious. He is itching to get back into action after a rolled ankle forced him out of the defeat to Wales in Cardiff.
Ashton's predatory presence was missed as England's pedestrian midfield tried and failed to bulldoze their way over the Welsh line.
England need Tuilagi to add a new dimension to their attack and Ashton will be prowling as usual, waiting for the right moment, for the gap to appear.
But as eager as he is to play, Ashton is conscious of not trying too hard.
"You can do that when you want to impress too soon. But as long as I do everything right and don't make any mistakes I'm sure I'll ease back into it," said Ashton.
"I'm sick of training. It's been nine or 10 weeks since that Heineken Cup final.
"I had to sit and watch the Wales game, which was hard to do. Hopefully I'll manage to get to the game this time and I'll be alright."
England return to Dublin on a revenge mission after Ireland wrecked their Grand Slam ambitions with a comprehensive victory at the Aviva Stadium in March.
This may be England's final preparation match for the World Cup, but there are some scores to settle.
"They beat us pretty convincingly and it's pretty hard to take," said Ashton.
"I think at that stage of the tournament we became a bit predictable in our play. We tried to run from deep and it just didn't work.
"They battered us really so yeah, we have a chance to go over there and get them back.
"It adds a bit of spice with what happened in the Six Nations. No-one in the squad is classing these as warm-up games.
"You've got to forget about the World Cup and get through this game."
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