ESSENDON has delisted midfielder Brent Prismall, defender Ricky Dyson and untried forward Ariel Steinberg.??

Steinberg, 20, who has not played a senior match in two seasons with the Bombers, has been guaranteed a spot on the club's rookie list for 2013 after signing a one-year contract this year.

Prismall has been invited to continue training with the club, keeping open his chances of being taken with a late pick in the NAB AFL Draft or pre-season draft.

The Bombers had given experienced pair Prismall and Dyson two weeks to train with the club and prove themselves after the club's first list lodgment at the start of November.

"We just want to see them train for a couple of weeks and make sure the effort's there and make sure their bodies can stand up to a whole pre-season," coach James Hird said two weeks ago.

But both have joined a number of other senior-listed Bombers to be delisted, including Sam Lonergan and Kyle Reimers.

Dyson, 27, enjoyed an excellent start to this season before an ankle injury ruled him out for five weeks at the end of the year. He spent nine seasons with the Bombers, playing 114 games.

Prismall, 26, joined the club at the end of 2008 after limited opportunities at Geelong, but has been restricted by injuries in his time at the Bombers.

He underwent a second knee reconstruction near the end of the 2011 season, that ruled him out for the first half of 2012.

Hamstring injuries meant he couldn't break through for a senior game this season. He played 36 games for the Bombers, for a career total of 61. ??

"It is a difficult time of year but we wish them both every success in the future," Essendon football manager Danny Corcoran said on Tuesday.

Essendon has now had 11 list changes ahead of next week's NAB AFL Draft, after also delisting Brendan Lee, Anthony Long, Michael Ross, Henry Slattery, Lonergan and Reimers.

Mark McVeigh retired and Angus Monfries was traded to Port Adelaide.

Callum Twomey is a reporter for the AFL website. Follow him on Twitter at @AFL_CalTwomey.