DANE Swan says the impact of the substitute rule contributed to the fatigue he suffered before Collingwood sent him to Arizona for a mid-season training camp last month.

The 27-year-old was second only to the durable Darren Jolly in consecutive games played at the club before this season, having appeared in 111 straight matches to the end of 2010.

He had not missed a game since round 12, 2006 (when he missed two matches with a hamstring injury) and had notched 121 consecutive appearances  before he was sent overseas ahead of the Pies' round-12 clash with Melbourne last month.

In an interview with the AFL website this week, Swan said he was "pretty beaten up" in the lead up to the US trip, and believed a 6-8 per cent increase in game time after the introduction of the subs rule had led to a loss of fitness.

"I certainly didn't come into the year thinking 'This is the year it's going to catch up with me and I'm going to need a break'," he said.

"Has the sub rule made me need a break? Probably, yeah. You don't get that extra rest on the bench and there's not a fourth person there for the whole game, so you are a lot more fatigued going into the last quarter.

"I would say it's definitely had an effect on players missing out this year."

Swan says the number of players able to play a full season will decrease because of the extra demands placed on players.

"You've seen Geelong do it over the last four or five weeks; they're trying to freshen up for September and you'll see a couple of other sides doing it now, too," he said.

"It's the way the game is - the rotations have slowed down and the injuries are taking its toll on a few clubs. We certainly won't take any risks.

"I think you'll see more players get a rest, especially the more important ones to the team, like the midfielders and power forwards who do a lot of the running, a lot of the work.

"They'll probably miss one game a year."

Swan has been one of the most rotated players in the past few seasons, and has had to get used to spending more time on field this season, with shorter breaks, often as brief as 20 to 30 seconds.

He said he was getting better at managing his field time to cope with the increased workload.

"At the end of the game, everyone is fatigued and the game opens up a lot because everyone is fatigued, and you feel that you're not running with the speed you were in the games last year," he said.

"In saying that, sometimes you just have to manage yourself in the first half -  just not really go as flat out as I would have last year for instance - just because the game is won at the end of the fourth quarter.

"You don't need to be in front at half-time; you just need to try and manage your workload in the first half so you can come out and give it a crack in the last half and last quarter when the game needs to be won.

"There's not a lot we can do about it. They're the rules and we have to play by them."