HAWTHORN is unsure when star forward Cyril Rioli will return to the club, after the Hawks granted him compassionate leave to be with his family. 

Rioli's father, also named Cyril, suffered a heart attack the week before the Grand Final, and had surgery last week.

As the Hawks kick-started their pre-season on Monday morning, Rioli was a notable absentee. 

Hawthorn captain Jarryd Roughead said the players had been in constant contact with Rioli, with his father expected to make a full recovery.

But a timeline on when the 28-year-old will return to the club is unknown. 

"I don't think we should put a timeline on it at all," Roughead said on Monday morning. 

"In situations like this footy becomes second. We've always been known as the family club and at times like this you need to be with your family. 

"His dad had the surgery last week and Cyril texted a few boys back saying all has gone well.

"We've had holidays but Cyril probably hasn't like the rest of us. He's been by his dad's side the whole time. For him to get away and enjoy a bit of a holiday and clear his head is probably a good thing."

The Hawks had nearly their full list training at Waverley Park on day one of pre-season. 

Veteran Shaun Burgoyne was missing, as he takes a break following the Virgin Australian International Rules series against Ireland.

Defenders Grant Birchall and Ben Stratton trained away from the main group as they continue their recoveries from knee injuries.

Key defender James Frawley, who missed the bulk of the 2017 with turf foe, trained for the full session with his teammates.

Midfielder Jaeger O'Meara trained with the main group for 45 minutes before breaking away to work on his kicking.

A persistent knee issue restricted O'Meara to six games for the Hawks in 2017, in his first season following the move from Gold Coast.

With many critical of the O'Meara trade, the Hawks will be keen for the former NAB AFL Rising Star winner to have an uninterrupted pre-season to launch his 2018 campaign.

But Roughead said there was no pressure on O'Meara.

"I think there's only pressure because you guys [media] talk about it," Roughead said. 

"Amongst our group we haven't put any pressure on him because we just want him to feel welcome, play well and get his body right.

"We saw towards the end of last year what he is capable of, I guess we're just scratching the surface in terms of what he can do for our footy club. So to get another pre-season into him here is going to be great for us."

Tom Mitchell began training with the main group before jogging laps on his own, while forgotten ruckman Jonathon Ceglar trained for the full session after missing last session following a knee reconstruction.

The Hawks head to New Zealand on December 4 for a training camp.

Jaeger O'Meara back in action at the Hawks. Picture: AFL Photos