ELEVATED rookie Kristin Thornton is set to play his first game for the Sydney Swans against Carlton on Saturday afternoon at the SCG.

Swans coach Paul Roos said Thornton, who spent 2008 on the sidelines after suffering a serious knee injury early in the year, had earned the right to replace injured defender Jared Crouch.

Spearhead Barry Hall is also likely to line up against the Blues, despite struggling with a groin injury sustained against Hawthorn two weeks ago.

"We’ll obviously monitor it with the doctors to make sure it’s not a progressive problem, but he played last week, so I’d expect him to play this week," Roos said before training at the SCG on Thursday.

Roos said it was frustrating that the veteran forward had been struck by injury so early in the year after completing one of his best pre-seasons.

The Swans match committee hadn’t considered resting Hall against Carlton, but Roos conceded that it may become an option should the 32-year-old's groin fail to improve.

"It’s tough and it’s tough on the player as well. They all want to play and to play to the best of their ability. But at some point, you do have to make the decision," he said.

"The difference this time is that it’s not an osteitis-type injury, it’s more just a muscle-type injury.

"But you do have to make a decision if it keeps grumbling on and they have 15 average weeks, when you could miss one or two and have 13 really good weeks. Hopefully we’re not at that stage at the moment."

Midfielder Luke Ablett, who was a late withdrawal last week with a sore gluteal muscle, was less certain of returning against the Blues.

"We’re still not sure, he’s touch and go this afternoon," Roos said.

"We’re going to have to wait and see. The team won’t get absolutely finalised until after training, but he’s still a bit doubtful."

Rookie ruckman Mike Pyke was also under consideration for Saturday’s game, but Roos said the former Canadian rugby union international would continue his development with the Swans reserves.

Thornton, who will make his AFL debut after four years on the Swans' list, was preferred for his ability to replace Crouch in the team’s structure, Roos said.

"Krisso comes in because he’s got an ability to play down back. Crouchy can play through the midfield [and] back, so you can’t really bring in a mid-forward type player," he said.

"He’s quite a versatile player and he’s also a really composed player. He’s a good decision-maker and obviously skilled, and that’s a pretty important part of the game now."