MELBOURNE, AUSTRALIA - MARCH 30: Ben Griffiths of the Tigers appears injured during the round two AFL match between the Richmond Tigers and the Collingwood Magpies at Melbourne Cricket Ground on March 30, 2017 in Melbourne, Australia. (Photo by Robert Cianflone/Getty Images)

Former Swans premiership coach Paul Roos has called for the league to consider bringing in a concussion sub as the frequency of head knocks continues to rise on a week-to-week basis.

In Sydney's close loss to Hawthorn on Friday night, the Swans lost Jake Lloyd to concussion in the opening minute of the match, while forward Sam Reid also succumbed to the injury after being ruled out during the half-time break with concussion following a tackle from Shaun Burgoyne.

With both players off for the entire second half, the Swans were down to two men on the bench, which may have played a part in the Hawks running over the top of them in the final stages of the last quarter to help them secure their fourth win of the season.

“I think the game needs to catch up to concussion,” Roos said post-game on Fox Footy.

“We are all supportive of what the doctors are doing now but 10 years ago those two players would have come back on.”

During his time as the head coach of Melbourne, Roos had to deal with several players suffering concussion, namely Angus Brayshaw, who is currently being monitored by the club after successive head knocks at VFL level earlier this season.

“I don’t know how you police it but I definitely would like to see a concussion-type sub coming into the game, particularly when guys get a knock 45 seconds into the game. It has a big influence,” Roos said.

“I don’t think any club would feel disadvantaged if a player came in at that stage.”

Geelong superstar Patrick Dangerfield was alongside Roos in Fox Footy's coverage on Friday night, and echoed his thoughts on the issue.

“For the team that loses that player, it makes a huge difference for the opposition team,” Dangerfield said.

“They can all of a sudden really spin the legs and ramp up the speed.”

According to AFL.com.au, 10 players were unavailable for selection this weekend due to concussion, with Richmond's Ben Griffiths joining Brayshaw on the indefinite list after a series of head knocks.