NORTH Melbourne midfielder George Wardlaw will be sidelined for up a month after straining his hamstring in a VFL practice match last week.

Scans have revealed the 21-year-old has suffered a low-grade strain in the same area as his previous injury.

Wardlaw, who has a history of soft-tissue injuries, was making his return to the field after hurting his hamstring in the club's match sim in early February.

"Scans confirmed a low-grade strain similar to the previous injury in the same area," North Melbourne head of performance Kevin White said.

"He has presented really well today and will look to return to play in the next 3-4 weeks."

Meanwhile, defender Riley Hardeman remains a chance to be fit for the season-opener after injuring his ankle in the practice match against Melbourne.

Tests revealed a medium-grade left ankle sprain for Hardeman, who was helped from the ground during the second quarter at Casey Fields. 

He is expected to be sidelined for 2-3 weeks.

"He will be looking to clear swelling and inflammation across this week before reloading once again and pressing his case for round one," White said.

Taylor Goad suffered a lateral ankle sprain at training on Wednesday and faces a 3-5 week recovery period.

"The initial phase is reducing swelling and soreness around the ankle before progressing with leg loading, which can take time," White said.

"Once functional and pain-free he will reload and build from there."