The Gunners turned down the chance to sign N'Golo Kante because they felt he didn't 'have enough' qualities for their side.
The ex-Leicester midfielder completed a £32million move to Chelsea last summer and is on course to be crowned PFA Player of the Year.
French journalist Julien Laurens, who had the inside scoop on Arsenal's scouting mission of the midfielder, revealed why they pursued other options.
He told BBC 5 Live: “They looked closely. Giles Grimandi the French scout for Arsenal went to see him a lot of they just didn't think he had enough to make it in their team.
“Then it was too late."
Laurens added: “And they tried to sign him last summer and he decided to go to Chelsea.
“It's a weird one, I don't know why bigger clubs were there when he was at Caen because it was so obvious."