Sheppard was concussed in the round-12 win over Carlton and also the round-22 loss to Fremantle.

The 30-year-old also copped a knee to the head in a pre-season clash with the Dockers.

Although Sheppard's head clash with Carlton's Adam Saad on June 6 was serious, he recovered well from the hit.

But a more minor incident in round 22 against Fremantle - when he played out the match before being diagnosed with delayed onset concussion - proved to be more serious.

Sheppard has struggled since then and decided to call it quits after consulting with medical experts.

"We just heard him speak to the staff and players and it was really emotional," Eagles coach Adam Simpson said.

"He's had a wonderful career that's been cut short. The way he spoke today was first class. He's going to be missed.

"It's just really sad it finishes this way. There were plenty of games left in Brad."

Sheppard's decision comes just over four months after premiership midfielder Daniel Venables was also forced to retire after failing to recover from the sickening concussion he copped in round eight, 2019.

Simpson is hopeful Sheppard won't be affected by ongoing concussion symptoms in his life.

Sheppard was nicknamed "Sheptember" by his teammates after producing a standout finals campaign during the Eagles' run to the grand final in 2015.

But his hopes of claiming a maiden premiership medal in 2018 were cut short after he tore his hamstring in the qualifying final win over Collingwood.

The concussion means Sheppard ends his 216-game career without a premiership, but not in Simpson's eyes.

"The way we look at him, he's a premiership player," Simpson said.

"He was so much a part of that 2018 season along with a few other players obviously Nic (Naitanui) and (Andrew) Gaff and Eric Mackenzie (who also missed out).

"But Shep in particular, all the way to that first final before he was struck down.

"And in 2015 we had this very short defence because a couple of our big fellas had knee reconstructions and he filled the void.

"He was playing on talls, playing on resting ruckmen, supporting others in the air. And then fast forward two or three years and he's playing on the best small forwards in the competition and doing a very good job.

"So versatility comes to mind and the ability to adapt as a player, that's what gives you longevity."

Simpson will wait for the dust to settle before formulating a plan to replace Sheppard.

Australian Associated Press