Nyon (Switzerland), Dec 13 : One of the fiercest football rivalries of recent times -- Cristiano Ronaldo versus Lionel Messi -- will be played out in its full glory once again when Manchester United take on Paris Saint-Germain (PSG) in a Champions League Round of 16 encounters over two legs in February-Match. The two stars have clashed numerous times while playing in the Spanish League. There will be many more side-stories to this key encounter besides the Messi-Ronaldo clash as Ralf Rangnick faces Mauricio Pochettino, one of the men who is the running for taking over on a long-term basis at Old Trafford, and the huge task ahead of United to get past the star-studded squad that includes Messi, Kylian Mbappé and Neymar. The two clubs are equal in terms of head-to-head with two wins apiece in four matches. United beat PSG in the last 16 in the 2018-19 season on away goals, while they met in the group phase last season with honours even as they won one match each. The two star-studded outfits were on Monday picked to face each other in the Champions League draw conducted at the UEFA Headquarters here with Atletico Madrid's clash with six-time winners Bayern Munich another potential humdinger. In other matchups Benfica of Portugal take on Spanish giants Real Madrid; Pep Guardiola's Manchester City face Villarreal, a club he faced many times in the Spanish League during his stint as Barcelona coach; former champions Liverpool have drawn a comparatively easier opponent in Austria's Salzburg; Inter Milan take on Netherland's Ajax Amsterdam; Italian giants Juventus have also drawn an easier opponent in Sporting club de Portugal while defending champions Chelsea have drawn French club Lille as their opponent. While all eyes will be on the Manchester United-PSG clash, the Atletico Madrid v Bayern clash will also get a lot of attention. Bayern are a squad with a lot of attacking prowess while Atletico are known for their stout defending and physical game. Bayern and Atlético have played eight previous fixtures, all in the European Cup - the most notable meetings their first, in 1974 final when a 1-1 draw was followed by a 4-0 Bayern victory in the only final to go to a replay. The draw ceremony ended a bit of confusion as the ball containing Manchester United's name was not included -- Liverpool included instead -- in the draw bowl while deciding the opponent for Atletico Madrid. Also, there were seven teams in the draw while picking opponent for Villarreal. The social media was abuzz over the two mistakes. The teams will be meeting in two-leg encounters. The first legs will be played on 15/16/22/23 February, with the second legs played on 8/9/15/16 March. The away goals rule no longer applies, so if aggregate scores are level after 180 minutes, extra time will be played, and if scores remain level after 210 minutes, penalties will be resorted to. /IANS