The former Republic of Ireland centre-back has slipped down the pecking order on Wearside this season but Grayson made a big call by giving him a first start in the 2-2 draw at Preston North End prior to the international break.
In doing so, Grayson risked the wrath of Sunderland fans by omitting such a tried-and-tested figure in Lamine Kone but the gamble paid off as O'Shea impressed.
It would be a surprise not to see the Irishman back in central defence when Queens Park Rangers visit the Stadium of Light tomorrow afternoon.
And the Sunderland boss says that the former Manchester United man still has plenty to offer after reminding people of his qualities at Deepdale.
“John’s got experience and leadership qualities – you don’t play for Manchester United, your country and this club for the number of years he has unless you’re a good character, and we just felt we had to have experienced players in that team to help us through," he told The Northern Echo.
"I think John showed what a good player he is and what he can still add to this team.”