Hawthorn defender Jarman Impey requires a knee reconstruction that will sideline him well into the next AFL season.
Scans have confirmed the worst after Impey hurt his right knee early in the second term of Sunday's upset win over Geelong.
Impey landed awkwardly in a marking contest and needed help from two trainers as he left the MCG.
Hawks coach Alastair Clarkson was hopeful post-game that Impey had not damaged the anterior cruciate ligament, but they have confirmed that he has.
Hawks football boss Graham Wright told the club website that Impey will undergo surgery this week.
"It's obviously really disappointing for both Jarman and the club, but he is in high spirits and remaining positive," Wright said.
"Jarman is such a valuable player for us and has been in impressive form."
The speedy 24-year-old defender was among seven Hawks who had played every game this season, for a career total of 116.
After four seasons at Port Adelaide, he is in his second year at Hawthorn and has been in career-best form.
Australian Associated Press