Although Arsenal have succeeded in extending the contracts of Jack Wilshere, Theo Walcott, Kieran Gibbs, Alex Oxlade-Chamberlain, Aaron Ramsey and Carl Jenkinson over the past month, the loss of Sagna would still be significant.
It would also further underline the sudden break-up of the Arsenal first team since 2011, with Cesc Fabregas, Samir Nasri, Gaël Clichy, Robin van Persie and Alex Song having all departed.
Sagna questioned the club's summer transfer strategy and said that he could not understand why Arsenal had sold Song as well as Van Persie.
He also admitted on Wednesday that Arsenal had been over-reliant last season on Van Persie.
"He carried the team all by himself last season he's doing it again with Manchester United this season," he said.