Tarrant was selected by North at pick No.15 in the 2007 NAB AFL Draft, but underwent three shoulder reconstructions in his first two seasons.
Early this year he moved from the club's forwards group for regular pre-season opportunities as a defender, which included a NAB Challenge match-up against Hawthorn's Lance Franklin.
Having found strong form with VFL affiliate Werribee in recent weeks, the 21-year-old will bolster North's backline in the absence of Nathan Grima, who is fighting to overcome an ankle injury.
"He's had a long, tough introduction to AFL footy with a lot of injuries ... and he's someone we're really keen to get into the side," coach Brad Scott said.
"He's a terrific athlete. At 196 centimetres, to have the agility and the speed that he's got is a real attribute.
"He played his junior footy as a forward but he's been more than capable in defence this year for Werribee.
"It's been a long time coming for him and I think he's just really excited to get out there and show what he can do."
Grima was clearly missed in last week's 35-point loss to Geelong, and Scott agreed that he had been North's most important defender this year.
For that reason, the 24-year-old will be given the time required to return to peak fitness before he's recalled.
"Unless he's absolutely 100 per cent fit, we won't risk him," Scott said.
"He's just too important to our defence to risk him in a big game like this."
Scott said a decision could not be made on Drew Petrie's availability until after Thursday's main session, but the forward will be selected should he get through.
Petrie fractured the fifth metatarsal in his right foot against Fremantle in round 10 - his comeback match from a similar injury to his left foot.
Though the vice-captain has only played one senior game in 2010, Scott suggested he was too good a player to bring back through the VFL.
"Watching him this week, he's trained so strongly ... we feel he's ready to come up," he said.
"As long as he's physically capable of covering the ground we need him to, then he's ready to play at AFL level.
"We talk about Jonathan Brown for Brisbane and Nick Riewoldt for St Kilda, but Drew really is our equivalent. He's just that important to our structure."
Scott expected the Swans to respond strongly to their surprise loss to Richmond last round, but said vision of their fourth-quarter fadeout hadn't been used to prepare his players.
And with eighth spot up for grabs, the result will shape North's season.
"It's fair to say that whoever wins this game is going to be more likely than the other to make the finals," Scott said. "It's as simple as that."
Scott was joined at Thursday's media conference by Australian Boomers coach Brett Brown.
This week, the Arden Street facilities have accommodated a mini-camp for 10 players ahead of the world basketball championships in Istanbul, Turkey.
