Veteran defender Dale Morris has reinjured his left knee in Sunday’s win against Fremantle at Marvel Stadium.

Morris was chasing a loose ball on the wing early in the third term of the 47-point victory over the Dockerswhen a sudden change in direction forced the 36-year-old's left knee to twist.

He was playing his first AFL game of the year, after four successful matches at VFL level recovering from an ACL injury to the same knee during pre-season.

"It's a suspected ACL injury, and beyond that obviously we'll just need to take some time to confirm it," senior coach Luke Beveridge said post-game.

"He's amazing. I patted him on the back at three-quarter time and he had this big smile on his face, which just shows the character and attitude of Dale Morris and we're really fortunate to have had him in our ranks for so long. 

"He's obviously been an enormously influential player at our football club for such a long period of time, a great example-setter, like a father figure (or) big brother. 

"For him to even be in that frame of mind and still be vocal supporting his teammates after he went down with the injury, speaks volumes for his integrity and who he is."

Morris has opted not to undergo the traditional ACL repair the past two occasions – the first of them to his right knee in February last year.

"When you consider with the other knee, that's fine, so it was exactly the same recovery, rehabilitation, turnaround and he hasn't missed a beat," Beveridge said.

"Then this one, I said publicly, in the (mid-week) press conference, I feel like he's come back even stronger this time – he's played better footy at state league level after this one.

"There's always a risk … (but) you look at his appearance, see the way he moves, and you know you've got all that stored experience and what he can contribute on-field for his teammates and his club, so it's just real bad luck to think he's done either side this late in his career."