Lukas Podolski
Cologne's Podolski reacts during the German first division Bundesliga match against Bayer Leverkusen in Cologne.

Former Liverpool midfielder Dietmar Hamann has questioned Arsenal's decision to sign Lukas Podolski and claims the striker remains unproven at the highest level.

The Germany international is reportedly close to finalising a £10.9m move to the Emirates after a standout season in the Bundesliga.

Podolski, 26, has notched 16 goals in 20 league games for Cologne as the side battle against relegation but Hamann, who played 59 times for his country, has warned Arsenal boss Arsene Wenger that signing the striker is a significant gamble.

"Podolski is obviously a very good player because he has shown it for a number of years in the [German] national team," he told Kick Off - via talkSPORT. "He's scored a lot of goals for them but the only thing is that most of his form, or all of his best form, is in the national team.

"He went to Bayern Munich a few years ago, he couldn't really make a breakthrough there, and obviously he's back in his home town of Cologne where he is loved, where he's their main player and he blossoms.

"He's scored a lot of goals this year but again, the one time he played for a big club, at Bayern, he didn't really cut it."

Podolski moved from Cologne to Bayern Munich after he burst onto the global scene in the 2006 World Cup, scoring three goals and winning the young player of the tournament award as Jurgen Klinsmann's Germany reached the semi-finals.

But the striker failed to recapture the form he showed at Cologne, despite winning the Bundesliga and playing in the Champions League for Munich. Podolski was eventually sold back to his boyhood club in 2009 and has emerged a more confident and reliable forward, epitomised in his impressive display against England in the 2010 World Cup.

Nevertheless, Hamann believes Podolski's frustrating time at Bayern Munich demonstrates the player lacks the ability to perform at a bigger club like Arsenal, particularly if the team is not built around his qualities.

"It's always different to play at a big club because you're one of many and at Köln he's their main player. He's scored more goals this season than the rest of the team [combined]," Hamann added.

"So he is in tremendous form this year but then again I always feel scoring goals for Köln, where he takes every free-kick and every penalty, is very different to scoring goals for Bayern Munich or Arsenal if he does come.

"He's a level-headed kid. He's not a bad person, I've not got any worries about him in that respect but then again if you come to a foreign country and don't know the language, sometimes that has other challenges.

"I just thought that with his failure to make an impact at Bayern Munich, I wasn't sure whether he was the right player for Arsenal."