Van Nistelrooy torn between Real, United
Ruud van Nistelrooy says it is 'impossible' for him to choose between Manchester United and Real Madrid.
The undoubted glamour tie of the round of 16 in the Champions League sees two of the Dutchman's former clubs clash.
Cristiano Ronaldo will return to Old Trafford for the first time as a player since his departure in 2009, with the first leg on February 13 at the Santiago Bernabeu before the second leg in Manchester on March 5.
Van Nistelrooy, 36, played under Sir Alex Ferguson for five years between 2001-06, scoring 150 goals for the club across all competitions, before moving to Real Madrid and winning La Liga twice.
"United or Madrid… Who do I want to win? Played my heart out for them both. Proud to have played for both. #impossible #MayTheBestTeamWin," van Nistelrooy tweeted.
Despite the stature of the two sides, their domestic campaigns have been contrasting so far.
United are top of the English Premier League table, six points clear ahead of nearest rivals Manchester City, while Real Madrid sit 13 points behind Barcelona in third.