Everton have confirmed midfielder Mikel Arteta sustained a grade two tear to his hamstring during the 1-1 draw with Birmingham.
Arteta had to be substituted within the first 10 minutes of the match at Goodison Park having pulled up with the injury while in a chase with Sebastian Larsson.
The club are not yet able to give any further details about how long the Spanish playmaker might be out for.
Source: PA