Olivier Giroud impressed with Laurent Koscielny's improvement

Arsenal striker Olivier Giroud believes that his teammate Laurent Koscielny is one of the best defenders in the Premier League.

The duo played together at Ligue 2 side Tours during the 2008-09 season, and Giroud is impressed with the centre-back's improvement since then.

"I'd say he's one of the best in the Premier League," Giroud told Arsenal's official website. "I think he can continue to [get even better].

"He's very respectable and serious in his work. You can trust him, and his behaviour on the pitch is important. I like when a guy concentrates and is serious.

"He is like a leader on the pitch, by his behaviour. He is important for the national team now, and he is a very important player for Arsenal. He is a very good player and a very good guy."

Arsenal have picked up five points from three Premier League games so far this season.