Veteran Brisbane Lions forward Jack Gunston is anticipating a significant stint on the sidelines after sustaining a knee injury against the Adelaide Crows on Saturday.

The Lions narrowly defeated the spirited Crows on Saturday afternoon at the Gabba, putting a significant dent in their slimming finals chances. However, it came at a cost for Chris Fagan's men.

During the second quarter, Gunston was tackled by an Adelaide defender, with his left knee appearing to hyperextend as a result of the weight of pressure applied in the tackle, as the veteran Lion was left visibly perturbed.

Channel 7 reporter Mitch Cleary revealed the latest on Gunston's situation on Saturday night, claiming the 'early word' is a 'medial injury' for the ex-Hawk.

"Yeah, the hyperextension. The early word out of the Lions camp tonight is a four-to-six-week medial injury, so four to six weeks," reported Cleary.

"That would have him touch and go [for a potential] semi-final [or] prelim final, so fingers crossed for Jack Gunston."

Cleary floated livewire goalsneak Kai Lohmann as the likely replacement for Gunston in Fagan's side going forward.

"Kai Lohmann [kicked] four goals in the VFL, you'd think he'd be the ready-made replacement (for Gunston)," he added.

The 20-year-old Lohmann, who has played just five senior games for the Lions this season, remains without a contract heading into 2024, with rival clubs likely to snap at the Victorian's heels if he remains without a deal.

Cleary also reported veteran rebounding defender Daniel Rich seems to have picked up an injury of his own, sustaining a hamstring ailment during a VFL clash against Williamstown.

"Word, too, that Daniel Rich limped off in the VFL with a hamstring injury of his own," Cleary said.

Brisbane faces Collingwood at Marvel Stadium next weekend, before closing their home and away account against St Kilda at the Gabba in Round 24.