The 23-year-old missed pre-season and the start of the Europa League and Premier League campaigns as he recovered from surgery on his injured groin but he was on the comeback trail after returning to full training last week.
Barkley suffered a hamstring injury at Finch Farm this week, however, and is set to be out for a further stretch, potentially ending his hopes of securing a move away from Goodison Park before the transfer deadline.
With his current deal expiring next year, Barkley has apparently turned down a new contract with Everton and the club were taking offers for him to hopefully wrap up a transfer this month.
Tottenham and Chelsea had been credited with serious interest but his ability to successfully pass a medical would be compromised by this latest injury if scans reveal any significant damage.
The Daily Mail report that Barkley's torn hamstring is likely to require surgery and that he would face at least three months in recovery.