Fin Smith’s most-recent fly-half cameo came when he was introduced in the 64th minute in Dublin on Saturday.
England were 10 points adrift at the time but tries from Tom Curry and Tommy Freeman helped the visitors close the gap to a 27-22 final scoreline, ensuring a losing bonus point.
Since the start of 2023, England have lost nine of 11 Tests starting with Marcus Smith at 10, with the only wins in that sequence both coming against Japan.
The Harlequins star prefers to play at fly-half but has been used several times by Borthwick as a full-back.
He was deployed at 15 in wins over Chile, Fiji and Argentina during the 2023 Rugby World Cup and played there for almost the entirety of England’s narrow 33-31 loss to France last season following a George Furbank injury.
Fin Smith insists that the pair, along with third centrally-contracted fly-half George Ford, have a strong enough relationship to withstand the strains of selection.
He said: “We’re competitive as anything on the pitch and then as soon as the whistle goes it will be ‘Oh, Marcus, what did you think of this?’ or ‘Fordy, what could we have done better here?’
“Just really just picking each other’s brains about stuff. I think that’s really positive.
“We’re all we’re driving each other to get better and ultimately it’s out of any of our hands who who plays in in the 10 shirt at the weekend.”
Willis, whose brother Jack plays for Toulouse and is therefore ineligible for selection for England, has been rewarded for his fine Saracens form.
The 26-year-old will make his first Test start after a couple of replacement appearances.
England suffered their record home defeat the last time they hosted France in the Six Nations, losing 53-10 with Marcus Smith starting at fly-half ahead of Owen Farrell.
France, who thrashed Wales 43-0 in their opening match of this year’s tournament, named their team earlier on Thursday with fly-half Matthieu Jalibert and wing Damian Penaud coming into their starting XV.
“He’s got a real box of tricks,” said Fin Smith of Jalibert.
“If we we give him time, space and and opportunities to run with the ball and put other people in space, it could be a long day for us.”
Hear more from Fin Smith and Steve Borthwick on Friday’s Rugby Union Weekly.