In the wake of Wednesday night's thrashing at the hands of reigning premiers Richmond, star defender Robbie Tarrant was admitted to hospital after suffering a knock to his kidney. 

Tarrant copped the knock in the first quarter of the game but still managed to play out the match, however the Kangaroos' vice-captain is expected to be fit for Round 1.

North Melbourne football manager Cameron Joyce told AFL.com.au Tarrant self-reported discomfort in the kidney area in the rooms after the game and the club took a precautionary approach.

"He copped a knock in the game last night to his kidney and spent the night in hospital. He suffered a low-grade bruising of his kidney," Joyce said on Thursday.

"We've got a four-day mini-break leading into this weekend, so he'll spend some time with his feet up and just rest.

"It's good that we've got some time off now, two and a half weeks leading into round one, so five or six days of rest should hopefully heal that and then he can get his preparation right for round one.

"We expect at the back-end of next week to assess it again, but I think he'll be right for round one."

Joyce said Tarrant should be discharged from hospital either later on Thursday or Friday morning.

This is Tarrant's first mishap of the pre-season and Joyce was is not concerned whatsoever that Tarrant would lose any fitness ahead of the Roos' season opener against Gold Coast.

"Robbie hasn't missed a beat in the pre-season and played both of the JLT games, so we're comfortable in terms of his preparation," Joyce added.

"He wouldn't need to play any more footy, so that's not an issue."