The La Liga outfit triumphed 4-1 in the home leg of their UEFA Champions League last 16 tie, taking them into the quarter-finals with a thumping 5-1 aggregate victory.
And Luis revealed coach Simeone's words before the match had inspired his side to such a convincing victory.
"Simeone asked us not to underestimate Milan as they are a great team despite things are not going well in Serie A," he said. "They scored a goal and levelled the match on the night, and another goal would have eliminated us.
"But then came Arda's (Turan) goal and we controlled the game from then on.
"We're delighted to make it this far. The bond with our fans is amazing, so we must continue and get as far as possible for them.
"The team is prepared to eliminate any opponent in the next round, but it will be complicated."
Goalkeeper Thibaut Courtois echoed those comments, saying: "I think over the two games against Milan we were really good.
"Maybe it was a bit difficult at the end of the first half (on Tuesday), but overall on the tie we were the better side."
