Emmanuel Petit believes there is "no excuse" for Arsenal's lack of spending in the January transfer window and has questioned the point of sacking Arsene Wenger if the club are not going to back Unai Emery.
The Gunners were limited to loan signings last month, as they struggle to nail down a place in the Premier League's top four, slipping to sixth over the weekend with defeat to Manchester City.
Ex-Arsenal midfielder Petit believes Emery has big problems in defence and that his former club have missed the chance to strengthen, having signed only midfielder Denis Suarez on loan until the end of the season.
"The frustration level must be very high for Emery, as in only his second transfer window as Arsenal manager he was told he cannot sign anybody," Petit told Independent.ie.
"You look at the money Manchester United, Liverpool and Manchester City spend and, unless you join them and put the cash on the table to compete for the best players, you are going nowhere.
"Tottenham are not spending money but they are in the position Arsenal were in a few years ago - building a stadium - but there is no excuse for Arsenal now.
"If you sack Arsene Wenger and then say to the guy who replaces him 'you have no money to spend on new players', I would ask; what was the point of sacking Wenger in the first place?
"Defensively, Arsenal have not been good enough this season, so I was surprised they did not try to sign defenders in January. But the problems they have will not be solved by signing a player or two.
"Clearly, the defence is a problem. The better teams are getting through them far too easily, and when I hear Emery say he is happy with his defence and he does not need new players in these positions, I'm pretty sure he does not believe this."