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.

โ€œMarcus 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%,โ€ Brisbane's General Manager of Football David Noble told lions.com.au.

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

โ€œThis operation should alleviate that, and we look forward to seeing him out on the field around the bye.โ€