The way Barcelona pressures its opposition is the key to the club's success, coach Luis Enrique said after a 6-1 demolition of AS Roma in the Champions League on Tuesday.

Last season's treble winner was at its breathtaking best with Lionel Messi back in the starting lineup, but Enrique focused on its work rate.

"We go into each game with the knowledge that we need to apply pressure, and the more that you do that then the better you get at it," the manager said after his team secured top place in Group E with a match to spare.