Sam Warburton says the physicality of Taulupe Faletau will be a worrisome factor for England when they face each other next week.
Faletau is set to go head-to-head with his cousin, Saracens number eight, Billy Vunipola.
The England back-row has made amassed over 50 carries in the previous Six Nations matches against Scotland, Italy and Ireland.
Warburton supports Faletau to come out on top in the battle between the two number eights.
“England have to stop Toby Faletau as well," Warburton told the London Evening Standard.
"He’s one of the best players I’ve played with. He’s gifted in the sense that he can do everything.
“It will be a massive battle for those two No8s and it will go a long way to deciding who wins that match. Billy has been a class act the last three weeks.
"He’s always been one of England’s go-to players and, if he has a good game, I’m sure England will go well.”
Warburton maintains that will it not be an easy outing at Twickenham, the Cardiff Blues stalwart is positive however they will be up for the challenge.
“We’ve beaten them four times since 2011 but both teams are pretty 50-50. England have been the most consistent team in the last few years of the Six Nations," he added.
“There will only be a score in it and a moment of brilliance will separate the sides. We won’t go worrying about anything going there from before, bar simply winning.”