By Michael Whiting

GOLD Coast coach Guy McKenna is at a loss to explain his team's second-half collapses after another terrible third quarter cost the Suns against Port Adelaide on Saturday.

After leading at half-time the past four matches, Gold Coast suffered another third quarter meltdown, conceding 7.7 to 0.2.

Whatever McKenna is saying – and the Suns are doing – at half-time, it simply isn't working.

Gold Coast has won just one quarter after half-time in its nine matches this season.

McKenna said the Suns have tried everything to arrest the worrying trend, but so far nothing had worked.

"We changed our warm-up at half-time, our messaging at half-time and all those sorts of things," he said.

"[That was the] first time we did that. We go around in circles trying to find the reasons ... we've just got to drive these boys to stay focused for longer."

McKenna said the problem was a combination of mental and physical, but denied a lack of effort was the issue.

He said the Suns had to play smarter.

"We've got to keep demanding and coaching the boys," he said.

"You steel their minds, they steel their bodies. We've shown enough when they do that, we're more than competitive but we're just unable to maintain that competitiveness in the mind for four quarters at the moment.

"Our hard ball gets were in front at half-time but the third quarter we had three or four guys charging in and they have one or two.

"Their two win (the ball) and get in on the outside and they're off to the races and kick easy goals. It's about getting the balance but you can't fault the boys' efforts, their willingness for the contest."

Sam Day – arguably Gold Coast's best with three goals – said the Suns could feel the change in momentum after half-time, but had trouble stemming the tide.

"We've worked on keeping the voice up and not dropping our heads," he said.

"I think it's about being smarter around the ball, not all going and chasing the ball. Being more switched on around the contests and knowing your role."

"When we play well, we play very well so I think our best is good enough to win games. It's just being able to let sides not get runs on like today and sticking at it."