Former-Arsenal midfielder Michael Thomas has revealed he thinks the Gunners midfield is too lightweight to challenge for major trophies this season.
Arsene Wenger's side currently lie seven points behind pace-setters Chelsea, and the Gunners are without a trophy since their FA Cup triumph in 2005.
And Thomas doesn't envisage that changing this year, unless Arsenal can bolster their midfield.
"Sometimes they are a bit brittle and haven't got the mindset to last the whole season," Thomas told BBC Sport.
Arsenal have lost Cesc Fabregas, Alex Song and Samir Nasri in recent seasons, and although Thomas believes Santi Cazorla is an excellent addition, the ex-Gunner still thinks his old side lack a Patrick Vieira type presence in central midfield.
"Cazorla is a fantastic player [but] I think they need someone to shut the gap - a holding midfielder in the style of Patrick Vieira to run the show," said Thomas. "These sorts of players are hard to come by.
"Arsenal play great football until, say March. They'll be up there. But when the serious side kicks in like the quarter-finals of cups and to win major honours, that's when I think they are a let-down.
"Manchester United, Chelsea, and Manchester City will go to the end and contest things. It's all about your mentality. I don't think Arsenal are hardened enough to win a title."
Arsene Wenger have started the season in good form, but failed their first big test at home to Chelsea. The Gunners lost 2-1 at the Emirates Stadium, and currently sit in seventh place.
They face Norwich on Saturday evening, and will be looking to jump back into the top four. Arsenal have never finished outside the Champions League qualification places under Arsene Wenger, and they'll be targeting another top four finish this season.