GRANT Birchall is one of the oldest rookies in the competition, but the veteran Brisbane defender says he's a new man after leaning down in the off-season.

The 33-year-old played just eight times in his final three years with Hawthorn, but got his body right and managed 16 games in his first season at the Lions.

After recovering from a hamstring injury suffered in Brisbane's preliminary final loss to Geelong, Birchall says he's even better in 2021.

The four-time premiership player has lost four kilograms and said he'd completed the entire pre-season program to date.

"I was a bit heavy last year," Birchall said.

"I lost a couple of kilos, so I should cover the ground a bit better than last year.

"I was coming off zero when I rocked up last year, so having that extra pre-season, extra work, will hold me in good stead."

As Brisbane juggled its list numbers at the end of 2020, Birchall was moved to the rookie list.

Although he said this would likely be his last season, the clever half-back said he had every intention of contributing heavily this year.

"I feel as though we're still in the window (to win the premiership), still got plenty of upside," he said.

"I want to be a part of that, I feel as though I'll be a better version of myself this year compared to last and that I can contribute well on and off the field."