Sydney Roosters secured a grand final place with a 36-20 victory over the Dolphins, but Connor Watson's availability remains uncertain.
Watson left the field for a head injury assessment in the 32nd minute after being struck while going for a loose ball.
He was first assessed as Category 2, before an independent doctor upgraded the incident to Category 1.
Roosters coach Trent Robinson said Watson was undergoing further tests at the stadium, and the club would decide whether to appeal based on the results.
"He's in the middle of doing his tests now to see where he's at so it's still watch this space on Connor," Robinson said.
Duke said the Roosters bench objected to the upgrade and intended to challenge the ruling.
"The Roosters bench were not happy that was upgraded to Category 1 and have already signalled their intention to challenge it," Duke said.