Pratt put pen to paper just as he began rehabilitation from a recent hip operation.
He says he is right on track to get back to full fitness, admitting his body had struggled in recent seasons.
"It should free up my back and hamstrings, which is what I had problems with last year," Pratt told kangaroos.com.au.
"The club and the surgeon are pretty confident that it's really going to help me with my football.
"It was good the club was willing to offer me another year after two pretty average years due to injury and form."
Pratt played just 13 games in 2010 following on from 12 the year before.
He said he was looking to return to the fitness and form that saw him appointed deputy vice-captain at the start of 2009.
"I'd love to get back to the form that I had between 2006 and 2008," Pratt said.
"If I'm playing well down back with Michael Firrito, Nathan Grima, Scott Thompson and Brady Rawlings it is going to make our backline very strong and the coach can just worry about the rest of the team and about getting our young midfield up and going."
While some AFL players are putting the feet up over their off-season break, Pratt is hard at work getting his body ready for 2011, trying desperately to lose some unwanted weight.
"I played at 92 or 93 kilos last year and I'm trying to get back to about 88 to 89. That would be nice, especially with the change of rules," he said.
Pratt said he was aiming at returning to running by the end of the club's high-altitude camp in Utah that begins at the end of October.
"I've had to be very meticulous. I can't run for 12 weeks. It's been five and a half weeks so far," he said.
"I've just started swimming again so I've pretty much been on the cabbage and water diet for the last four weeks trying to keep my weight and skin folds down, but it's all part of the job. You can't just kick back like you used to."
