NORTH Melbourne's Jaidyn Stephenson has hit back at high-profile critics who questioned his competitiveness in the loss to Collingwood.

Stephenson agreed with some of the criticism, admitting he was a "liability" towards the end of Saturday's contest as the Kangaroos threw away a lead.

But the 23-year-old said that was due to back and leg injuries that ultimately forced him to be substituted out of the game.

"I wasn't able to compete properly in those contests and that was due to my pain in my leg and my back," Stephenson told the Nine Network.

"I ran off and said, 'I'll get subbed out, I'm a bit of a liability here at the moment'."

Ex-St Kilda and Fremantle coach Ross Lyon was scathing in his criticism of Stephenson, accusing him of being a "non-competitor".

Former Port Adelaide midfielder Kane Cornes told AFL.com.au's The Round So Far that Stephenson "significantly cost" his side against the Pies.

The Kangaroos led by 26 points at three-quarter time but went down by seven, extending their losing streak to 14 matches.

"All the people that commented have achieved a lot more than I have and it does hurt, I suppose," Stephenson said.

"You've got to be resilient and probably the negative stories sell more than the positive stories.

MEDICAL ROOM Check out the full injury list

"I suppose the disappointing thing is that these blokes make comments without actually indulging in the finer details or the circumstances as to why an event may occur."

Last-placed North Melbourne takes on Richmond in round 18, with Stephenson's availability unclear after he had scans on Monday.

Stephenson is in his second season of a five-year deal with the Kangaroos after being moved on by Collingwood.