The 28-year-old had seemingly returned to form in the first half of the Pies’ big win, taking two marks inside 50 and booting his first goal since round 17, but took no part in the second half after copping a poke in the eye just before half-time.
In what may be yet another injury blow to the sixth-placed Magpies, Cox was taken to a specialist in the game’s aftermath.
Collingwood coach Nathan Buckley said the severity of the injury was unknown.
“We are not anticipating it to be anything major, but our doc was concerned enough to send him away pretty quickly,” Buckley said in his post-match press conference.
“He has blurred vision, which makes it pretty hard to play, but we will see how that settles.”
The Magpies will look to win consecutive games for the first time in almost two months when they take on Melbourne at the MCG on Saturday.