Hamann has followed the German youngster's progress closely and delivered a glowing report on Brendan Rodgers' third summer signing.
"He's a very talented player," the 2005 Champions League winner told Liverpoolfc.com.
"He's a technically gifted player of Turkish origin; these players always handle the ball very well. He's also not short of pace and he's physically strong.
"He left Bayern Munich last year and went to Bayer Leverkusen and had a good season. He played more or less every position for Leverkusen; they had a few injuries and he had to play in a lot of positions.
"He still has to find his best position. I'm sure that Brendan will have a position in mind. But when you have got players who are versatile, it's almost like having an extra player in your squad, because if they stay fit and you can use somebody in two or three positions, it's a big asset to the club, the team and the squad."
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