The 27-year-old was set to become an unrestricted free agent at the end of the season, but the Dogs announced on Thursday that they had secured his services until the end of 2021.

Liberatore underwent a knee reconstruction, his second, after rupturing his anterior cruciate ligament in round one last season and missed the rest of the campaign, but has returned to top form this year.

"Being loyal to my teammates is a big thing for me," Liberatore said.

"I've been part of this group for nine years now, and I'm happy where I am.

"It's been good to come back from injury and play every game so far this year and nice to sign on for two more years to have that comfort around the future.

"I'm really looking forward to the back half of the year ... how we can grow this year and over the next couple of years.

"This group has the promise and the talent to get back to the top and we've shown that ability in certain games this year."

Liberatore, son of Bulldogs Brownlow Medal winner Tony, has played 128 matches since being recruited as a father-son selection at the 2010 draft.

Australian Associated Press