Unai Emery's decision to take Mesut Ozil out of the Arsenal starting line-up means that nobody can afford to rest on their laurels, according to Lee Harper.
Ozil has been the Gunners' standard-bearer since moving to north London in 2013 from Real Madrid.
The former Germany international has forged a reputation as one of the Premier League's elite playmakers, breaking several assist records for Arsenal while also racking up more than 40 goals in his 208 appearances.
Emery, however, has used Ozil sparingly in recent weeks, with the star making just two appearances in all competitions over the course of November.
And Harper believes that the Spanish manager has sent a message that below-par performances will not be tolerated even from Arsenal's most experienced players.
“I think Emery’s been fantastic. He’s given everyone a breath of fresh air, changing a few things around tactically and bringing in new ideas," the ex-Arsenal keeper told Love Sport Radio.
“The fact he reportedly left out Mesut Ozil because he wasn’t happy with his work-rate tells you that no one is safe.
“Everyone knows that they’ve got to go out and perform and give 100 per cent."
Arsenal resume their Premier League campaign on Sunday with a huge north London derby at home to rivals Tottenham.
A place in the top four is on offer if the Gunners can win, and Harper has called on his old employers to leave nothing to chance against third-placed Spurs.
“I think it’s going to be tough on Sunday, as tough as the game against Liverpool," he added.
“Tottenham are buoyed from a really big win against Chelsea and they have some very good players.
“I think it’s a bigger game for Arsenal. Tottenham would be more satisfied to come away from the Emirates with a point whereas Arsenal could do with all three to keep themselves right in there at the top.
“If they lost to Spurs there would be a six-point gap between them and you don’t really want that at this stage of the season.
“They need to keep on their tails so hopefully they’ll get the win.
“They’ve passed every test they’ve faced so far on this 18-month unbeaten run and that’s a fantastic achievement, but they’ve also drawn four or five games recently and now they’re 10 points down on Manchester City.
“They need to pick up some wins as well and there’d be nothing better than picking up a win on Sunday.”