David Luiz has backed Chelsea team-mate Andreas Christensen to step up in Antonio Rudiger’s absence and help the club reach the Europa League Final.

Rudiger has been ruled out for a minimum two months after having surgery on the left knee injury he sustained against Manchester United on Sunday.

It means Christensen will start alongside Luiz at centre half in the first leg of their Europa League semi-final at Eintracht Frankfurt on Thursday.

The Denmark international has played in every game of the competition in 2018-19, but this is his biggest game in European club competition since making a telling error against Barcelona in the last 16 of the Champions League 15 months ago.

Christensen has struggled to stay a first team regular ever since but Luiz told Standard Sport: “Andreas is a great player, a great boy. I like the way he thinks about football and looks to play the game.

“People always seem to want to remember what they want to remember, we can’t do anything about that.

“What happened to Andreas against Barcelona is in the past and people shouldn’t talk about it. It is not nice to talk about it. Chelsea lost against Barcelona, it wasn’t Andreas losing against Barcelona.

“Have I tried to help him since what happened last year? Yes. He is a great friend and he listens a lot. We always help each other.

“He has a lot of quality when he has the ball at his feet on the pitch. He is good at reading the game, he is an intelligent and clever defender.”

Chelsea have won 11 and drawn one of their Europa League ties so far, but face their toughest test to maintain their unbeaten record in Germany.

Eintracht Frankfurt are fourth in Bundesliga and have highly fancied striker Luka Jovic up front. The Serb, who has been strongly linked with a move to Real Madrid, has scored 25 goals this term.

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But Luiz has revealed he has been talking to his former Chelsea team-mate Salomon Kalou to get tips on the Frankfurt side and Jovic.

Kalou, who was part of the Chelsea side that won the 2012 Champions League, is now at Hertha Berlin and they were able to hold Eintracht Frankfurt goal-less in the Bundesliga last Saturday.

Luiz added: “I have spoken to Salomon about how they play. They had a game against them the other day and drew 0-0 against them. But I can’t tell you what he told me!

“But I have watched Jovic ahead of the tie. He is doing an amazing season and is a great striker. When forwards are confident like he is right now it is even more difficult. His confidence is so high because he has been working for that.

“Eintracht have a fantastic team, they like to play three at the back. They play with a lot of physicality but also great players with technique. It is going to be a tough game for us.

“But I am looking forward to this semi-final. I work hard every day to be on the pitch for games like this and try to do my best.”