Port Adelaide midfielder Karl Amon will miss up to one month of football after scans revealed a fractured patella.
Amon suffered the injury against Geelong in round 10 when he took a knock to his knee, although scans revealed the injury was worse than first thought.
The 21-year-old was a late withdraw against Hawthorn last Thursday night, and was replaced in Port Adelaide's side by Jimmy Toumpas.
“We felt it was a minor knock originally, but when he couldn’t come up for the match against Hawthorn we decided to get it scanned,” Port Adelaide head of high performance Darren Burgess told the club's website.
“The scans showed a fracture there, unfortunately it looks like a 3-4 weeker for him.”
Amon's injury looks to be the only major injury concern for the Power, as Chad Wingard, Dan Houston and Cam Hewett are all set to undergo fitness tests during the week.