Ross Barkley is facing the prospect of another spell on the sidelines for Everton.
The want-away midfielder had resumed training with the Blues last week after undergoing surgery on a groin problem barely a month ago.
Barkley missed the start of Everton’s Premier League campaign but was anticipated to return to action in time for next Monday’s trip to Manchester City.
However the England international suffered a fresh setback as he sustained a hamstring injury during a training session on Monday morning.
The 23-year-old will now discover whether the extent of the injury will prolong his first-team absence amid ongoing uncertainty over his Goodison Park future.
Ronald Koeman revealed earlier this month that Barkley had informed him of a desire to leave Everton in favour of pursuing a ‘new challenge’.
However the Dutchman also admitted that no offers had been tabled for the Wavertree-born player despite interest from both Tottenham and Chelsea.
Everton had offered Barkley a new long-term deal as he prepared to enter the final 12 months earlier this summer but failed to agree terms.