Brisbane defender Marcus Adams is set for an extended stint on the sidelines, after learning he will need more surgery in a bid to fix his troublesome knee.

Adams will undergo arthroscopic surgery on Monday in a bit to fix a recent injury, which will set him back for another 6-8 weeks.

“Marcus had been close to returning the past few weeks, however there is a slight impingement issue in his knee that is restricting him getting back to 100%,” Brisbane's General Manager of Football David Noble told lions.com.au.

“He has completed 90% of his rehab program, predominantly straight-line work and the issue is when we have increased his agility work.

“This operation should alleviate that, and we look forward to seeing him out on the field around the bye.”