The Bulldogs announced that Morris suffered a partial tear to an anterior cruciate ligament on Thursday during training.

A full ACL tear means a knee reconstruction that would sideline Morris for up to 12 months.

But the Bulldogs will put the 35-year-old on a rehabilitation program in the hope that he will recover without any surgery.

Morris is one of the AFL's toughest players and is famous for his resilience.

"I've played with 'Moz' for six years now and I know how much of a warrior he is. He's had setbacks along his career and every time he's bounced back tremendously," teammate Jack Macrae said.

"He's just so strong willed and minded. We'll see him at the club with a smile on his face on Monday, I'm sure of that.

His professionalism and how he drives the group is just first class.

"I have no doubt in my mind that he'll play this year and when he comes back he'll get back to his best footy without any lag time."

The Bulldogs admit it could be 12 weeks before they know definitely how long Morris will be out of action.

"Given the type of injury this is, and the unknown nature of the recovery time, we will work with Dale over the coming eight-12 weeks to more accurately determine when he is able to return to the field," Bulldogs medical services manager Chris Bell said.

"This strategy will maximise the chance of Dale being able to play a meaningful part in the 2018 season.

"While this is not a common injury, there have been other similar cases in the AFL where surgery was not required for the healing process."

Morris has played 241 games and overcame two broken vertebrae to be a key member of their 2016 premiership team.

Morris missed 10 weeks of last season because of a broken arm and leg.

He is on a year-by-year contract.

Australian Associated Press