Mertesacker has declared Lacazette as top class.
"His record in 2017 is brilliant," he said.
"The way he has settled in has been top class and it makes us feel as though there's more to come."
Just last week, Gunners manager Arsene Wenger expressed his satisfaction with the way Lacazette had bedded in.
"He plays his game, I think he's a player who connects well with others," Wenger said.
“He's not only a goal getter, you want him to participate in the build-up and be on the end of things."