THE resilience of reigning premiers Hawthorn continues to be tested in a season of setbacks, but returning coach Alastair Clarkson believes that's been the case for 18 months.

Clarkson missed five games himself while recovering from Guillain-Barre syndrome, but is back to coach Friday night's clash with North Melbourne at Etihad Stadium.

His first tough decision is whether midfielder Sam Mitchell plays in the VFL, AFL or not at all after suffering a serious hamstring injury two months ago.

"He's touch and go," Clarkson said, revealing little prior to Thursday's light training session.

Equally challenging will be hamstrung Cyril Rioli's two-month stint on the sidelines, while Josh Gibson (pectoral) is two weeks away from returning.

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Clarkson suggested injuries are part of life at a football club, and the Hawks handled them just fine in 2013.

"I'm not pleasantly surprised," Clarkson replied when asked about his side leading the ladder with an 11-3 record despite injuries to key personnel.

"Because we won the flag last year, everyone thinks it was all rosy and we must have had a stellar year (with injuries).

"We had four knee reconstructions last year. We haven't had as many injuries this year as we did last year."

Clarkson admitted his own mid-season absence at the club was "pretty unique and created a little bit more hysteria".

But it didn't show on the field, caretaker coach Brendon Bolton finishing with a flawless record.

"We had to respond to a fair amount of duress and instability last year," Clarkson said.

"That's a strength of a footy club - being able to cope with adversity and finding a way to still perform on the field and get results.

"We've been able to do that a fair bit over the last 18 months."

The hot-and-cold Kangaroos are coming off arguably their most disappointing performance of the season, a four-point loss to the Lions in Brisbane.

Clarkson said the Hawks would be preparing for North's best.

"We go into every game expecting a full-on assault from the opposition," Clarkson said.

Rioli has returned to Darwin but will be back at the club next week as he attempts to regain full fitness before finals.

"He's 24 years-of-age. We think we're slowly getting on top of it," Clarkson said of Rioli's recurring hamstring issues.