SYDNEY Swans key forward Sam Reid insists he'll line up in Saturday's Grand Final against Hawthorn, despite being subbed out of last weekend's game with a knee injury.

Reid re-injured his right knee in last Friday night's preliminary final win over North Melbourne.

He told SwansTV the fear of missing the Grand Final made for a sleepless night after the preliminary final, but that any fear had since been replaced with complete confidence in his body. 

The 22-year-old was moving freely without strapping on Wednesday and said that having managed the issue for most of the year, he knew what had to be done before Saturday's season decider.

"[I'm] ready to go…I've got a pretty good idea of what needs to be done to get myself right for this weekend," Reid said.

"It's something that I've managed throughout the year and figured out how to get on top of.

"I had that confidence in my head, but I didn't sleep much on Friday night."

Saturday's game will be Reid's second Grand Final, after he kicked a goal in the Swans' 10-point win over the Hawks in 2012.

His brother Ben, who plays at Collingwood, has also played in two Grand Finals (2010, 2011).

Reid said a lift home with his father after last Friday's game helped it hit home just how lucky and rare his opportunity to win a second flag was.

"I was driving home with Dad on Friday night after the game and he said he played 10 years and played two finals and lost them both – I'm 22 and in my fifth year and this is my second Grand Final," he said.

"My brother and I have been pretty lucky, he's also played in two Grand Finals.

"It's a good experience to have and I'm excited for another opportunity to win one."