The explosive midfielder/forward was due to come out of contract at season's end but has put pen to paper on a two-year extension.

"I think signing before the season just takes a little bit of stress off me and I'm honestly just very excited," Petracca told the club's website.

"Whether I signed now or at the end of the year, I always wanted to stay at the club."

Petracca, the No.2 draft pick in 2014, has booted 79 goals in 85 AFL games and can play both through the midfield and up forward.

He kicked 22 goals in 2019, finished fifth in Melbourne's best and fairest and is expected to kick on with more midfield time in 2020.

A slimmed-down Petracca racked up 38 disposals and booted three goals in Melbourne's opening pre-season match against Adelaide on Saturday.

"Christian is a passionate Melbourne person who we have watched develop each year and we are delighted that he has agreed to this extension prior to the season," Melbourne general manager of football Josh Mahoney told Melbourne's website.

"He's an exciting young player who can play a valuable role though our midfield or forward.

"We look forward to watching him continue to improve, along with the rest of our playing group."

Australian Associated Press