The shock departure of vice-chairman David Dein in April has now been replaced by growing concerns over the future of manager Arsene Wenger and star striker Thierry Henry.
Wenger has reportedly become frustrated by a lack of funds available to stengthen his young squad, while talk of talisman Henry moving to Barcelona refuses to go away and seems to be gathering pace.
Inter midfielder Vieira, who left the Gunners to join Juventus in July 2005 after nine years at the club, told the News of the World: "It is a difficult time for Arsenal because the players need to know what's going to happen.
"It is a crucial time. David Dein has left and, whether you like him or not, he has been a fantastic servant for the club.
"With him going the players are asking what is Arsene going to do. Maybe if he goes they may say 'I don't want to stay'.
"Players need to know who's going to be the manager, which players are coming and which are going. The next few months will be very important for Arsenal."