Sol Campbell is definitely out of Sunday's Community Shield, Arsenal's Premiership opener against Newcastle and England's friendly against Denmark.
The 30-year-old centre-back, who has a calf injury, could even miss September's World Cup games against Wales and Northern Ireland.
Arsenal boss Arsene Wenger said it will be "two to three weeks" before Campbell regains full fitness.
The match against Chelsea on 21 August may also come too soon for him.
Wenger said: "I'm confident that Sol Campbell will not have a season like he did last year, but nobody knows how many games he will play this season."
Philippe Senderos and Kolo Toure will again form Arsenal's central defensive partnership in Sunday's Community Shield against Chelsea.