Former Germany manager Beti Vogts has criticised Lukas Podolski for taking things easy during his time at Cologne.
An experienced international with 103 caps for his country, Podolski moved outside of his home nation for the first time in his career by signing for Arsenal during the close season.
"I am happy that Podolski has left Cologne. He had too many friends in the city," Vogts told The Sun.
"He got praised as a great runner if he ever got back to defend three times in a game. He got an easy ride and he believed his own publicity. But now he has a coach at Arsenal in Arsene Wenger who will make him work hard in training as well as matches.
"If Podolski fails to train properly twice or three times he won't get games. That is the way to develop him into a true professional."
The 27-year-old has two Premier League goals in his first six games for the Gunners, scoring in victories against Liverpool and Southampton.