Arsene Wenger's side can end the long wait for silverware with a victory over Hull City at Wembley on Saturday, and after a campaign which saw Arsenal lead the Premier League for 128 days before finishing fourth, the German defender believes a cup win would be the platform for the club to go on to achieve more.
|5/1||Arsenal are 5/1 with Bet365 to beat Hull City 2-0 on Saturday|
"It would be a big step for our team," Mertesacker told Arsenal's official website.
"We went through a lot of difficulties, we were top of the league before we dropped points and then came back to fourth position.
“We have won five games [in a row and] we want to continue with that - it looks like we are back on track.
"There were a few years when we lost some key players every season.
"This year we stayed together and got the right additions. It has changed a bit now we keep important players, as you can see.
"Eight players have extended their contracts and the manager is likely to do that as well, so the core is all together.
"That has changed the belief, the togetherness and the confidence. We think we can achieve something from this group."
Mertesacker has become a key member of the Gunners' back four since his move from Werder Bremen in 2011 and thanked the club's supporters for helping him through a rocky start to his career in north London.
"I had a hard first season but they encouraged me so I have to give them credit," he said. "Especially in my first season they always covered me and always backed me up and gave me that bit of confidence you need as a player.
"It's good to have a manager who backs you up in difficult situations but also when the crowd does not get nervous when you get the ball and they are chanting your name instead. That's the difference."