Pears appeared set to become one of the best key defenders in the competition when, in his second season, he played all 23 games in 2009 and finished sixth in the Bombers' best and fairest award.
But a horrendous run with injuries over the past three seasons and Essendon's enviable key-position depth has reduced Pears to a fringe player at Windy Hill, with the 23-year-old managing just four games so far this season.
Other out-of-contract key defenders on the radar of opposition clubs include North Melbourne pair Nathan Grima and Luke Delaney, West Coast's Mitch Brown and, to a lesser extent, Carlton youngster Matthew Watson.
Industry sources say the clubs most actively in the market for a tall backman are St Kilda, the Brisbane Lions and West Coast, all of whom AFL.com.au understands are among Pears' potential suitors.
Despite Pears' struggle for opportunity at Essendon, the West Australian is no certainty to leave.
"There is definite interest in Pears from other clubs, but Essendon is really keen to keep him," an industry source said.
"In the end you suspect his decision will come down to whether Dustin Fletcher retires at the end of the season and whether Michael Hurley stays in defence."
Grima has come onto Adelaide's radar after a solid start to 2013.
The North defender, who turns 28 in August, has battled knee and back injuries in his six seasons at Aegis Park, but has missed just one game this year with soreness.
Grima has a connection to the Crows and South Australia, having been coached by Adelaide's national recruiting manager Hamish Ogilvie as a junior with the Tassie Mariners and played in Central Districts' 2007 SANFL premiership.
He has been an automatic selection for North when fit over the past four seasons and AFL.com.au understands the Roos intend to begin contract talks with him within the next month.
Delaney, 24, has been unable to break into North's team this season but his outstanding VFL form with North Ballarat has attracted the interest of clubs including the Brisbane Lions, Geelong, West Coast and St Kilda.
Delaney, whose younger brother Cameron also plays at North, attracted interest from the Lions and Geelong in last year's trade period, but he remained at North when a suitable deal could not be struck.
Luke is likely to seek a trade at the end of this season if he continues to struggle for senior opportunities.
Eagle defender Brown unsuccessfully sought a trade to St Kilda in last year's trade period after struggling to get a game behind fellow tall backmen Darren Glass, Eric Mackenzie and Will Schofield.
The 24-year-old Victorian has enjoyed far greater opportunity with the Eagles this season, playing 10 of their first 12 games, but continues to be widely linked to the Saints.
Watson was the No.18 pick in the 2010 national draft but after playing 11 games in his first two seasons, has not been able to break into Carlton's team this year.
He turns 21 this month and has work to do on his one-on-one contests but has attracted some interest from opposition clubs.
Nick Bowen is a reporter with AFL Media. Follow him on Twitter @AFL_Nick
