Marchant backs England to front up to physical France in Six Nations
Steve Borthwick's outfit can claim the title for the first time since 2020 if they beat Les Bleus in Lyon with a bonus point and Ireland suffer a defeat by more than seven points to Scotland earlier in the day in the final round of the tournament.
France have included prop Uini Atonio and lock Emmanuel Meafou, who both weigh an impressive 145kg, in their starting lineup for the game to face an England side fresh from last Saturday's statement-making win over table-topping Ireland.
"I think physically is the main thing," Stade Francais midfielder Marchant told AFP on Thursday.
"With the French, what I've learnt is when they're physical and they get things right they're a hard team to stop.
"As we know with England, when they come out of the blocks and firing and they take it to a team, get their gameplan right, there's not too many teams in the world that can stop them," he added.
Marchant made the last of his 26 international appearances during last year's Rugby World Cup, where England finished third.
His move to the French capital has brought a temporary pause to his Test career with Borthwick unable to select players based outside of England.
Other leading England players including former captain Owen Farrell and prop Kyle Sinckler are also joining the Top 14 due to the ongoing financial problems in English rugby.
"I'm locked in at Stade for the next two years," Marchant said.
"When I signed I knew I was here for a good stint so it was more of a get settled in as quick as I could, get the French going well, keep learning as much as I could to get a seamless transition.
"I'm excited to be a part of Stade and hopefully it's not the last time I play for England," he added.
'Good spectacles'
Marchant has helped 14-time French champions Stade Francais and their famous pink shirts to the number one spot in the Top 14 table with eight rounds of the regular season to play.
Highlights have included a home win over second-placed Toulouse and last Saturday's trip, despite defeat, to La Rochelle, both played in front of raucous sold-out crowds highlighting the health of domestic French club rugby.
"We went to La Rochelle last weekend and the stadium, the crowd, were unbelievable," Marchant said.
"There was a life about it. The energy was very much towards the football kind of side of things in England.
"They're really good spectacles," the former Harlequins centre added.
On Saturday, Marchant, who can also play on the wing, will be watching the game, nicknamed 'Le Crunch', in a pub in England during a break weekend in the Top 14.
In Borthwick's midfield will be Ollie Lawrence and Henry Slade, who were crucial in the victory over Ireland with powerful Manu Tuilagi among the replacements for the first time since October.
"They've been going really well together," Marchant said.
"They complement each other well. Ollie doing his thing with ball in hand and Slade doing his thing when he’s putting the boys in space.
"It's nice to see Manu back on the bench, hopefully he gets some game time because having someone like that on the bench is not bad at all," Marchant added.