#4 Keep Verratti marked
"There are very few players who know what to do when they’re not marked. So sometimes you tell a player: that attacker is very good, but don’t mark him." - Johan Cruyff
Marco Verratti dominated the midfield in the first leg and played the more vital role in Paris Saint-Germain's historic 4-0 win at Parc des Princes. The Italian was given a lot of space, and he made every inch of it count.
With a pass success of 92% in the reverse fixture, the 24-year-old midfielder ensured that the centre of the pitch was all PSG's. He even managed to grab an assist.
Keeping Busquets or Rakitic on the toes of the Italian all the time is essential. Cramping him for space and ensuring that he's not able to make those crucial passes to Rabiot or Matuidi is going to win the midfield for Barcelona.