Former Arsenal captain William Gallas felt Andrey Arshavin didn't make the most of his career.
The pair played together with the Gunners, where Arshavin was between 2009 and 2013.
Gallas told Ball Shorts: "It was too much for him. It was too difficult for him to be stable and maintain discipline.
"I don't think he was strong enough mentally. Arshavin was indeed talented, but he did not have a great career.
"The Premier League is a very difficult league. It's not even about the fact that there are a lot of games there. You need to give yourself in training every day."
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