By Rob Kelly
The France internationals have been friends since spending a season together at Ligue 2 side Tours during the 2008/09 campaign.
Giroud has been impressed with the improvements Koscielny has made in the intervening years but believes there is still more to come from him.
“I’d say he’s one of the best in the Premier League,” the striker told Arsenal Player. “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.”
You can watch the full interview with Olivier on Arsenal Player now.Copyright 2016 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source