But Vunipola, whose brother Mako also played a vital role in the Lions' series win in Australia last summer, will miss the match after sustaining an ankle injury as England beat Ireland on Saturday.
Ben Morgan is expected to step into Vunipola's shoes and Faletau expects a ferocious battle with the Gloucester man - but he knows his 21-year-old cousin will be a big miss for Stuart Lancaster.
"It would have been nice to go up against him," he said. "It would have been fun but tough.
"He's done so well with his ball-carrying and is a hard man to stop but he is also very good at the breakdown - once he is on the ball he is tough to move.
"It's a big blow for them to lose Billy. Ben Morgan has done well coming off the bench but Billy's a big loss."