SportItalia says Vidal has a contract offer on the table from United worth €8 million-a-year - net, which is worth over double his Juve salary.
The issue is set to come to a head this week with Juve preparing to leave for their Asian tour.
If Vidal is left out of the squad, it will be a sure sign he is on his way to United.
The midfielder's agent is this week meeting with Juve officials about United's offer. If Juve agree to match the English club's proposal, Vidal will stay.
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