The England international missed the opening win over Tottenham and could sit out the rest of August with mild thrombosis.
Manchester United utility man Phil Jones has been ruled out for at least three weeks with mild thrombosis.
The England international sat out Saturday's 1-0 victory over Tottenham, after which United confirmed he is set for a longer spell on the sidelines.
The club tweeted: "Phil Jones, who was not involved in today's matchday squad, has mild thrombosis and will be out for a minimum of three weeks."
Jones' injury will not only see him miss United's Champions League playoff tie with Club Brugge, but he likely is doubtful for England's European Championship qualifiers against San Marino and Switzerland in early September.