Gold Coast's ruck depth has taken a hit with Zac Smith to miss up to 12 weeks with a PCL injury.

The 31-year-old suffered the setback in the opening minutes of Saturday's VFL practice match against Brisbane at Metricon Stadium and did not return to the field.

"Subsequent scans have confirmed some damage to his PCL," Gold Coast's general manager of football Jon Haines said.

"Whilst disappointing for Zac, we know he will attack his rehab with 100 per cent commitment and look to return as quickly as possible."

Although Smith did not play a senior game in 2020 after returning to his inaugural club following a four-year stint with Geelong, his injury could be costly.

In Jarrod Witts, Gold Coast has one of the most durable ruckman in the competition, but the cupboard is now extremely thin beyond the co-captain.

Following the off-season trade of Peter Wright, the only genuine option is untried 20-year-old Academy graduate Matt Conroy, who is beginning his second season in the system.

Since coming to Gold Coast from Collingwood ahead of 2017, Witts has played 79 or 83 possible games, and not missed any in the past three seasons.

Twelve weeks is likely at the long end of Smith's recovery and the club is hopeful he could return sooner.