(Reuters) - AC Milan must raise their level as the Europa League enters the quarter-finals with some European heavyweights awaiting the Serie A side, manager Stefano Pioli said after his team's 3-1 victory at 10-man Slavia Prague on Thursday.

First-half goals from Christian Pulisic, Ruben Loftus-Cheek and Rafael Leao helped Milan ease past the Czech side with a 7-3 aggregate win in the last-16 tie.