Real Madrid will be looking for its fourth straight win in the Champions League when it plays AC Milan on Wednesday.
The match is Madrid coach Jose Mourinho's first return to Italy since he led Inter Milan to the Champions League title in May.
"Going back to the San Siro is the same as going home," Mourinho said. "It's a shame it is Milan vs. Real Madrid instead of against Inter. ... It would have given me the chance to thank everyone at the stadium for those great two years I had there."
Madrid leads Group G with nine points, five more than Milan. Madrid beat Milan 2-0 two weeks ago with Cristiano Ronaldo and Mesut Ozil scoring.
"It's important for us to be group leaders after our game in Milan," Madrid defender Ricardo Carvalho said. "Our goal is to secure first position as soon as possible and that's why it's important to earn a good result there.
"We were better at the Bernabeu and Milan's players will want to prove they can defeat us."
Ronaldo has scored 10 times in the last four games, including two in a win over Hercules on Saturday.
"Cristiano has been scoring many goals for quite some time," Carvalho said. "He looks at the goal constantly and he needs to score to feel comfortable on the pitch."
Zlatan Ibrahimovic has been the main inspiration for Milan so far this season and has three goals in three Champions League matches.
"Tomorrow against Real Madrid we have to do everything differently to what we did in Spain," Ibrahimovic said.
"At the Bernabeu Real dominated, we were slow and played poorly," he said. "Luckily there's another match and if we do things differently from in Madrid we can win and show we are as strong as Real, if not stronger."
Last year, the teams drew 1-1 at the San Siro. Karim Benzema opened the scoring for Madrid, but Ronaldinho hit back for the hosts with a penalty.
Madrid leads the Spanish league, one point ahead of Barcelona. Milan, meanwhile, is third in the Serie A, five points behind surprise leader Lazio.
On Saturday, Milan lost to Juventus 2-1, its second loss of the season.
"On Saturday our performance against Juventus was good, one our best starts to the season," Milan coach Massimo Allegri said. "The only thing that was missing was the result.
"When you play these types of games you cannot allow yourself to play poorly," Allegri said. "Tomorrow we really have to put the pressure on Madrid."
Ronaldinho missed the game, but hopes to be back.
"I feel fine and over the last few days I have done all the work necessary and I want to play my part," Ronaldinho said. "A big game against Real is one you want to play and do your best in.
"In the first leg the two early goals made life extremely difficult for us. Now we have to concentrate on what the coach said so we can get the three points."