MICHAEL Hartley has been rewarded for his breakout season in Essendon's backline by signing a new two-year contract.

The defender was excellent in his first season in the red and black, taking on a number of key roles against the competition's best tall forwards.

He was contracted to the end of this season but the extension will tie him to the club until the end of 2018.

The 23-year-old was delisted by Collingwood at the end of 2013 after failing to play a senior game, but relaunched his career by playing in the VFL with Coburg.

The Bombers drafted him last year and he was a beneficiary of the suspensions to the 12 Essendon players, playing 19 games for the year.

"The playing group is in a really good place, the next few years are going to be exciting for the football club and it's great to be a part of it," Hartley said in a club statement.

"I'm pumped that I'm going to have the opportunity to play alongside Michael Hurley down back.

"He's one of just a number of really experienced players who will come back next season, but we're under no illusion that it's going to take plenty of hard work if we're to be competitive."

Hartley's re-signing leaves the Bombers with 12 players on their list out of contract for next year, including regular senior players Courtenay Dempsey and Martin Gleeson.

Youngster Jayden Laverde also remains unsigned with rival interest growing in the exciting youngster.