By FOX SPORTS Staff
Varane has been one of Real's breakout stars this season; the Frenchman joined the club from Lens in 2011 and recently earned the plaudits for his superb displays against Barcelona in the Copa del Rey.
The 19-year-old also gave a credible account of himself in the first leg of Real's last-16 Champions League clash against United which ended in a 1-1 draw.
And Keown, regarded as one of the best defenders the Premier League has ever seen, claims Varane will be able to stop Van Persie, who has been in sterling form for the Red Devils this season, when both teams clash at Old Trafford for the second leg of the tie.
"I watched Real Madrid's win over Barcelona on Saturday and again Raphael Varane stood out for me," Keown wrote in the Daily Mail.
"At 19 years old, he must be the best young central defender in Europe and I understand why Real Madrid paid close to £9million for him at the beginning of last season.
"Watching him up against Robin van Persie again will be fascinating, assuming Jose Mourinho keeps the Frenchman in his team.
"Pepe was left on the bench for Varane in the first leg so it is now a big call for Mourinho whether to repeat that selection."
Keown expects Van Persie to be eager to end his mini goalscoring drought against Real but believes Varane's numerous defensive qualities will help him cope with the Dutch international.
"The way Varane reads the game is exceptional," Keown explained.
"He is rarely beaten to the ball, not just because of his pace but because his positioning is so good.
"He sees danger early and he positions his body very intelligently, standing side-on so he does not lose ground by having to turn 180 degrees to run with a striker.
"At 6ft 3in, Varane is strong in the air too and composed on the ball.
"He had a few nervous moments in the first leg at the Bernabeu but so did Van Persie, who missed a couple of chances he would expect to convert.
"Van Persie has gone four games without scoring now - his longest run in a United shirt - and ending that drought will surely be the key to Sir Alex Ferguson's side progressing.
"He will be desperate to score his first Old Trafford goal for United in the Champions League but Varane has the tools to make life difficult."
Varane has thus far made 27 appearances for Real this season.