Adams last played in the round 21 defeat of Carlton, when he was subbed off with a rib injury.
In the days that followed, the 29-year-old began experience concussion symptoms that have lingered in the five months since.
The concussion is the latest in a series of injury setbacks that have cruelled the late-blooming defender's career.
Adams was restricted to only 27 games across three seasons with the Western Bulldogs, then missed all but one game of the 2020 season with a foot injury.
"Unfortunately, Marcus is dealing with a serious injury that will unlikely see him play in 2023," said Lions general manager of football Danny Daly.
"While he is making some progress in his recovery from concussion, he continues to experience symptoms and his health and wellbeing remains the top priority.
"The club is fully supportive of Marcus and his recovery, and he will remain involved with our footy program."
The Lions were at their best with Adams in the backline this season, losing two of the four games he didn't play.
But the injury has thrown Adams' future into doubt. His contract expires at the end of 2023 and if he misses the entire season, he will go more than 18 months without a game and turn 30 in that time.
Jack Payne replaced Adams in the backline in the weeks immediately after his injury but the Lions will bolster their stocks with an extra player from the pre-season supplemental selection period as well.
Meanwhile, Collingwood key position player Nathan Kreuger has undergone a reconstruction on his right shoulder and will miss the start of the season.
Kreuger, who was sidelined for an extended period with a left shoulder injury last season, injured his right shoulder at training just before the holiday break.
He is expected to be available within the opening six rounds of the new campaign.
Magpies captaincy candidate Darcy Moore has resumed running after a bone infection (osteomyelitis) delayed his start to pre-season.
"We are pleased to see (Moore) back running and re-integrated into the football program," Collingwood football boss Graham Wright said.
"Due to the nature of Darcy's setback, we will continue to monitor his progress closely and will provide further updates in due course."
