LIVERPOOL -- Former Liverpool defender Alvaro Arbeloa has warned his visiting Real Madrid teammates to be ready for a "special" Champions League atmosphere and says even Cristiano Ronaldo is wary of the challenges of playing at Anfield.
The European champions are on Merseyside preparing for Wednesday's Group B match against Brendan Rodgers' side.
Madrid are top of the group after winning their opening two Champions League matches, beating Basel 5-1 and Ludogorets 2-1 -- and have also won their last five league matches.
Liverpool, meanwhile, sit third after following up their win over Ludogorets with a defeat against Basel in Switzerland.
Arbeloa, 31, spent two-and-a-half years with Liverpool after joining from Deportivo La Coruna in January 2007. He helped the Reds to reach that year's Champions League final, which they lost to AC Milan.
He was also part of the Liverpool side who beat Real Madrid 4-0 on their last visit to Anfield in a 2009 Champions League last-16 tie -- completing a 5-0 aggregate win.
Madrid are a far stronger side now than they were five years ago, but Arbeloa believes they must still be wary.
And he says he has been backed up in his assessment by Real's former Manchester United forward Cristiano Ronaldo.
Arbeloa said: "I've told my teammates about the tremendous atmosphere that will face them. It is a special game for Liverpool after five years out of the Champions League.
"Even Cristiano has mentioned in the past that this is the most difficult away ground in the Premier League.
"It's tough to put into words what it's like to play here. You have to experience it for yourself.
"These are special occasions. As a player, you need to experience it at least once.
"Liverpool need to win, so it is an important match for them. And it's a special day for me. I'm really happy to be back."
Liverpool have been inconsistent this season, and sit fifth in the Premier League after losing three of their first eight matches.
Even though the Reds were poor in beating bottom club QPR 3-2 on Sunday, Arbeloa still sees them as a threat.
"Even if Liverpool had lost 10-0 at QPR, I'd still be coming here worried," said Arbeloa. "I know what Liverpool are capable of on a European night.
"We must be prepared for a very tough, tough game. Liverpool are more in need of the points than we are, and that makes it very tough for us.
"The Anfield atmosphere will work against us. We have to be focused."
Ronaldo arrives at Anfield in top form, having hit 15 goals in just seven league games this season. He has scored 18 times in his last 10 appearances in all competitions.
Asked if Ronaldo was in the best form of his career, Arbeloa said: "That's a recurring question with him. He is just incredible. Confidence wise, he is at the highest level he could be."