BRISBANE Lions forward Jonathan Brown has insisted his fitness was not a concern despite admitting he was so dehydrated he suffered blurred vision in the AFL season-opener in Perth.

Brown broke a horror injury run last season after being nursed through training, engaging in a program of pilates, and playing every game for the Lions to win the Coleman Medal with 77 goals.

But alarm bells were ringing last Saturday when Brown became dizzy and disorientated at half-time against West Coast.

However, the 26-year-old downplayed the incident, saying he wasn't the only player suffering from the combination of Perth's dry heat and Subiaco's long ground.

"I had a bit of blurred vision at half-time, I lost a little bit of weight but there were a lot of players in that boat," he said at the Gabba on Wednesday.

Brown returned to the field in the second half but reportedly had trouble making it back on to the Subiaco ground because he was so dehydrated.

However, the Lions star said: "As soon as I entered back into the arena I was fine.

"My faculties were fine, I had a rest in the third quarter but that was more a rotation thing."

Despite the concern at the long break, the Lions co-captain still booted six goals in Brisbane's 16-point loss to the Eagles.

Brown said the 5.40pm local time start at Perth also did not help.

"Certainly it was the dry heat over there, I'm sure it was in the 30s in the first half and because it is daylight saving over there it was a bit of a day game I suppose," he said.

"But I think early in the season, round one, big ground - all those factors combined… it probably caused players to cramp up and not run out the game."

Plagued by a string of injuries in recent seasons, Brown insisted that if anything his match fitness was better because of the Perth game.

"My match fitness is a little bit off but that would have to be pretty close (to full fitness) after running around on such a big ground," he said.

Brown will again be the Lions' spearhead in their blockbuster against Collingwood at the Gabba on Friday night.