Arsenal are facing a battle to finish in the Champions League spots this season after a run of bad results.
The Gunners are now six points behind fourth placed Liverpool following Saturday’s 3-1 defeat to West Brom.
And Mustafi wants his Gunners team-mates to use the international break to help them refresh and get back to winning ways.
Shkodran Mustafi admits Arsenal need to up their game to finish in the top four
"We haven't been playing to our potential,” Mustafi told the DFB website.
“As a team we can use this international break to refresh and then start again when we go back.
"When we meet up again in London we need to roll up our sleeves.
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“We want to finish in the top four because Arsenal wants to be playing in the Champions League next year.
"I think it's risky to justify our position by saying we have played two games fewer than Liverpool.
“If we had beaten West Brom, we wouldn't be sixth."