Mesut Ozil has admitted he does not feel he was worth the fee Arsenal paid to sign him from Real Madrid.
The Germany international joined the Gunners for €50 million (£42.5m) in the summer of 2013 and came under scrutiny for inconsistency in his first two seasons.
And Ozil has insisted that the price-tag was excessive, as he believes no footballer is worth such a sum.
"Nobody in the world is worth €50 million," he told Express.
"We must be careful in football that we do not lose the grip of our credibility."
Arsenal have been drawn in the same group as Bayern Munich in the Champions League and Ozil feels they are coming up against a side capable of winning the trophy this term.
"Bayern are one of the strongest teams in the world and they can beat just about any opponent," he added.
"Some other teams will have a say in it, but why can't Bayern win the competition? They are in a narrow circle of favourites.