Much of the Swans’ success in the past six years has been generated by stellar contributions from the likes of Barry Hall, Michael O’Loughlin, Leo Barry and Brett Kirk.
But on the eve of round one, Roos said the unknown toll that several years of physical sacrifice had taken on the Swans’ key players was a concern.
“When you do have guys who have played and are battle-tested and maybe even battle-weary after six finals campaigns, some of them can drop off really quickly and I think that’s probably the unknown with our team,” he said before training at Lakeside Oval on Thursday.
“How many of them can hang on and how long for? And by that, I don’t necessarily mean the 32, 33-year-olds. We’ve seen Tadhg Kennelly at 27 decide to go back to Ireland because of his body. We’ve seen Nic Fosdike at 28 decide that he can’t go on because of his knee.
“And it’s not unique to us. We saw it at Port with Roger James and [Josh] Francou, with Vossy and Leppitsch and those guys up in Brisbane and we’ve already seen it a little bit with West Coast as well.
“It’s just the reality of playing so many tough games and that’s probably the greatest unknown.”
While all the club’s senior players bar O’Loughlin and Barry will take the field in round one against St Kilda, it’s a different story for the young Swans.
Emerging players Nick Smith, Matthew Laidlaw, Tim Schmidt and Patrick Veszpremi are all unavailable through injury and Roos said that was equally concerning.
“[Those] guys who were probably looking to play at this time of the year are all injured, so it’s almost first come, first served and the older blokes have stood up,” he said.
“It’s funny how the older guys seem to be a bit more resilient at this time of year. Guys like Hally and Kirky, and Crouchy are playing round one, which [Crouch] hasn’t done for a while.
“It’s not as big an issue in round one because all our older players seem to be up and going, but at some point, it does put a bit of pressure on your list if you have a lot of guys who struggle to get through big amounts of training.
“The other thing it does is that [the young players] just can’t improve, because they can’t get out on the track often enough.”
While the young Swans have struggled for fitness heading into the season, Roos said the team that would take the field on Saturday night was in robust health.
“But I think the cause for optimism is the health of the senior players at the moment,” he said.
“That’s always a big thing. The players that we’ve got going out on Saturday night, I don’t have any worry about any of them getting through a game in terms of a fitness point of view.”
