Cox will have surgery later this week after tearing a retina in his eye in Sunday’s win over the Gold Coast.
“Mason has been advised that after the surgery he will need a number of weeks rest which means that he will not play again this season,” Collingwood GM of Football, Geoff Walsh told the club website.
“You don’t take risks with situations like this. A second appointment with a specialist this morning confirmed that Mason suffered a tear to his retina that needs surgical repair.
“It is obviously a disappointment, especially for Mason, but importantly he is expected to make a complete recovery. We look forward to his return to the club.”
Beams has undergone shoulder surgery that was originally scheduled for post-season. It was brought forward to ensure he is right to go for the 2020 pre-season.
The star midfielder has endured a tough 2019 campaign, undergoing hip surgery in June before taking a leave from football to address his mental health.