Everton boss Ronald Koeman insists Ross Barkley needs to improve ‘in all the aspects’ of his game, and has held talks with the midfielder to ensure he is aware of the required raising of his performance levels.
Koeman decided to take Barkley off at half-time during Monday's Premier League contest at the Stadium of Light, which was goalless at the break before the Toffees ran out 3-0 winners.
The Dutchman later said the 22-year-old England international "didn't show the level" expected of him.
And, speaking on Thursday ahead of Everton's home clash with Middlesbrough on Saturday, Koeman stressed Barkley needs to up his game "in all the aspects".