Sunderland brought in two out and out strikers during the summer transfer window.
Sunderland brought in both James Vaughan and Lewis Grabban over the summer, but there was an expectation that they would do more to improve their attacking options.
However, Grayson insists that Sunderland did all they could to bring in another forward on deadline day.
“There wasn’t a load of strikers available on deadline day,” he said.
“I don’t think you saw too many leaving clubs on deadline day – why should any club let strikers go to potential rivals?
Both Grabban and Vaughan have endured difficult starts to their careers at the Stadium of Light.
Vaughan has already become a figure of ridicule at Sunderland, due to his lack of goals.
The former Bury and Everton man has netted just once in his first 14 appearances for the Black Cats.
Grabban, meanwhile, is currently out injured – and has not featured in any of Sunderland’s last four Championship matches.
Sunderland return to action after the international break, when they take on Queens Park Rangers at the Stadium of Light.
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