Arsenal defender Per Mertesacker has expressed his belief that Nicklas Bendtner's impact against Cardiff City displays the club's strength in depth.

The Denmark striker came off the bench to score the opening goal in the Gunners' 2-0 success on New Year's Day.

Mertesacker believes that Arsenal have players in reserve who can make vital contributions to the side.

"It was a vital goal from Nicklas," he told Arsenal's official website. "He did it against Hull as well when he stepped in for Olivier Giroud, and this time you saw how vital it is to have the depth in the squad.

"It's important to have a second proper striker who comes in and just does what he usually does.

"Normally when you have a lot of chances at the end you struggle a bit and maybe you concede a goal, but at the moment we are quite solid at the back and don't concede a lot."

Arsenal sit top of the Premier League following the win, one point clear of second-placed Manchester City.