Sunderland were beaten 5-0 by Celtic in a pre-season friendly at the weekend.
Sunderland were beaten 5-0 by the Bhoys, in what was a disastrous pre-season match for Grayson’s side.
The Black Cats were thoroughly outplayed by the Scottish champions in front of their own fans, and big questions are now being asked – as the new campaign grows closer.
Kone has fielded a great deal of criticism for his display, and was taken off early in the fixture.
And Grayson suggests that the Ivorian was having fitness issues, after playing a great deal of football recently.
Grayson said: “He wasn’t in the best physical condition – he was feeling fatigued at half time.
“Fair play to him, last week 85 minutes and 90 on Wednesday so (Saturday) was maybe too much of a game for him, the number of minutes he’s had.
“He was one of a few players who struggled out there, so you can’t blame Lamine for the result.”
Kone’s attitude was called into question at Sunderland last season, when he appeared to put in a number of half-hearted performances.
There are still rumours that Kone could leave this summer, but if Grayson can get the powerful defender back to his best he would be a major asset in the Championship.
Sunderland get their competitive campaign under way on Friday evening, when they take on Derby County in the Football League curtain raiser.
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