BRISBANE coach Chris Fagan says he should have selected Rhys Mathieson sooner after a "wonderful" performance by the rugged midfielder in Saturday's victory over Greater Western Sydney.

Mathieson gathered 23 disposals and a match-high 10 clearances in the 40-point triumph, vindicating the coach's decision to promote him for his first senior game of 2022.

Now in his seventh season, Mathieson has been dominating at VFL level, but unable to add to his 63 career games and force his way into Fagan's 22 as the Lions have been locked in the top four and relatively healthy until the chaos of the past fortnight.

GIANTS v LIONS Full match coverage and stats

However, given his chance as one of seven changes from the team that lost to Essendon six days earlier, Mathieson grabbed it with both hands.

"We selected him today because we knew the Giants have big bodies and we're mindful teams seem to be tagging Lachie (Neale), so we thought Rhys would be a good inclusion this week," Fagan said.

"I'm sitting here thinking we should have thought that a little while ago and maybe picked him a little sooner.

"Typical of Rhys, he gets his opportunity, he puts his hand up and delivers for us. Ten clearances is a wonderful effort by him."

Mathieson played with his typical aggression, earning seven free kicks as he beat Giants opponents to the ball and frustrated them in the process.

He was one of a number of standouts, with Fagan praising four-goal midfielder Hugh McCluggage and No.1 ruckman Darcy Fort, who shouldered the main mantle in the absence of Oscar McInerney (health and safety).

Fagan said he was most pleased with his team's defence, limiting the home team to just 21 inside 50s through the first three quarters when victory was bankrolled.

He was looking forward to Dayne Zorko, Daniel Rich, Jarrod Berry and Jaxon Prior all becoming available next week after overcoming soft tissue injuries.

"We were pretty worried about the game to be honest," he said.

"I feel today was a very good step in the right direction.

"We've had selection headaches the last two weeks because we've been losing players, and next week we've got selection headaches because we've got players coming back.

"That's a good position to be in."

Fagan's counterpart Mark McVeigh was at a loss to explain his team's second poor showing in as many weeks following a heavy loss to Port Adelaide.

He was particularly critical of the Giants' midfield – both their inability to win the contest and their lack of defensive running once the ball was lost.

He said their rucks, led by Matt Flynn against the Lions, "haven't been up to it".

"We were outworked," McVeigh said.

"They were harder and they were more relentless than what we were.

"I continually thought it was an effort thing for us."

McVeigh said the players had to have a good think about what they wanted out of the final five rounds of the season, with finals well-and-truly out of the equation.

"I think what they do need to find is what they want for the rest of the year individually and as a team.

"You can't just have a heavy fade out and we all sail off into the sunset and finish poorly.

"They're aware of that. I know they've got together after the game by themselves, which is great.

"I won't be letting up in my approach to train them hard.

"When a loss happens like this there's always consequences and that could be from a selection point of view, but I'll be upping the ante in the way we train and approach the next few weeks."

McVeigh confirmed Josh Kelly was in the concussion protocols.