Wolfsburg goalkeeper Diego Benaglio faces around a month out of action after undergoing surgery on his injured right knee.

The 26-year-old Switzerland international has not featured for the Wolves since before Christmas and has admitted defeat in his hopes of avoiding an operation.

He told the club's official website: "It just wasn't getting any better. Normal training or a game just wasn't possible.

"It had gotten to a point where I just couldn't take the acute pain in my knee anymore."

Meanwhile, Koln have been boosted by the news that star striker Lukas Podolski has returned to training after several weeks out of action with a back problem.

The 24-year-old Germany international told his club's official website: "I'm feeling much better again.

"It's now up to me to make sure that I return to full match fitness as soon as possible and stay fit. I can probably return to match action this weekend or the following week."