The reassurance that he was wanted was all it took to convince St Kilda champion Robert Harvey to prepare for a record 21st season at AFL/VFL level.

Nursing an arm in plaster following an arthroscopy to replace a ligament in his left wrist, Harvey announced on Thursday that he would be back in Saints colours in 2008, chasing the premiership that's eluded him since his debut at Moorabbin as a 17-year-old in 1988.

The dual Brownlow Medalist admitted he's been wrestling with retirement for the past three or four years and was convinced at the start of this year that season 2007 would be his last.

"I've always been wary about wearing out the welcome mat," Harvey said.

"Even though physically and mentally I still feel great and I still feel like I'm contributing and going in the right direction … it's very difficult to know what to do.

"I love the club but I didn't want to make the wrong decision and hopefully I haven’t."

He said his decision to continue was based on two main factors - his fitness and feedback from the club that he was wanted, appreciated and, even at 37, thought to be still capable of matching it with the competition's best.

"If there was any hesitation at all (from St Kilda) I was certainly going to finish," he said.

"I have been more than happy with how the club have treated me and my relationship with the club over 20 years and that was probably the main thing for me, to know what the feeling was.

"I didn't know which way the club wanted to go and that was a big factor for me, to know that if there was a spot that I was keeping that was holding someone back, then I really needed to know that."

According to senior coach Ross Lyon, who suggested recently that he would be prepared for Harvey to commit to play half-a-season next year if that's what was required to encourage him to stay involved, the club's position was always clear.

"It was based on form and fitness and love of the game and enjoyment of training … but it was really easy," Lyon said.

"We were always keen … but it was really his decision."

Harvey is poised to become the first player whose AFL/VFL career has extended to 21 consecutive seasons, bettering Michael Tuck's 20 years (1972-91) during which the durable Hawthorn star played a league record 426 matches.

The career of the VFL's oldest-ever player, Vic Cumberland, spanned 22 years, but was interrupted by travel and service during the First World War.

Harvey said his decision was made easier by the strong support of his family and team mates and his firm conviction that the Saints would be in the premiership mix next season and a force for the next five to 10 years.

"Why would they keep me if that wasn't the case? Absolutely we're in that market, but if I had won one (a premiership), I reckon I would be back on the peninsula with my feet up," Harvey said.

"I've enjoyed as much as anything my footy in my 30s than I have any other time in my career.

"The club's been a great place to be and it still is. I think it’s on the wave of a really great period."

Harvey said the current board upheaval at Moorabbin was irrelevant to his decision to play on.