The Gunners have struggled for goals and points in the Premier League this season.
They suffered another home defeat, this time to Wolverhampton Wanderers on Sunday - a 2-1 reversal.
It is a result that has left them in the bottom half of the table.
Barnes believes the lack of quality in the squad is the Gunners' biggest issue.
"[Striker and captain Pierre-Emerick - who has struggled for goals this term - ] Aubameyang is not by himself going to save Arsenal, he's not a Messi or Ronaldo in their heyday, so he would have to be part of a team," Barnes told BonusCodeBets.co.uk.
"If you look at Harry Kane and what he's doing at Tottenham, he's now playing a different role and being creative, working hard defensively and doing lots of things for the team regardless of how well they're doing.
"Arsenal need to start playing with a bit of confidence, find some identity and understanding then you will see the best of Aubameyang and all the other players."