MELBOURNE, AUSTRALIA - AUGUST 19: Tom Mitchell of the Hawks runs with the ball during the round 22 AFL match between the Carlton Blues and the Hawthorn Hawks at Etihad Stadium on August 19, 2017 in Melbourne, Australia. (Photo by Scott Barbour/Getty Images)

Hawthorn legend Dermott Brereton has raised concerns over his former club’s ability to return to the finals.

The Hawks missed September action last year for the first time since 2009 and Brereton believes they, alongside Collingwood, are the two most difficult sides to predict in 2018.

Brereton says the positive form of the club without injured veterans makes him unsure whether their return will necessarily boost the team’s on-field performance.

“The thing he (Clarkson) had up his sleeve has already been done last year with Jack Gunston and James Sicily back, and Will Langford as a pressure forward, even though he couldn’t kick the ball through the goals,” Brereton told 1116 SEN on Friday.

“That worked really well for them.

“This is a cop out, but I think the two teams that are the hardest to get a read on for 2018 are Hawthorn and Collingwood.

“The Hawks, after the halfway mark last season, were about the third best performed team.

“That was when they lost Ben Stratton, James Frawley, Cyril Rioli, and they’ve had a host of other players, and of course Jaeger O’Meara.

“They lost all those players, they had 18 operations throughout the season, and they were still the third best performed team after the halfway mark.

“Counteracting that was the fact they weren’t very good when they had those good players in.

“Will they be better with those champion players coming back? I can’t see them dramatically improving.”

Brereton was however buoyed by the fact the injury-riddled Jaeger O’Meara played in Hawthorn’s intra-club match after a solid pre-season.

The former Suns’ midfielder is an unquestionable talent and could be the key to the Hawks revival according to Brereton.

“There is always concern because of that injury history,” Brereton said.

“It is a worry about how many games he has been put on the field.

“It’s a concern but if someone is really injured, and they’re battling away, as per the history of O‘Meara, you don’t play them in intra-club games.

“So you have to take it on face value that things are going alright. You just have your fingers crossed the boy is able to get through.”

Hawthorn face the Bulldogs and Carlton in the pre-season before meeting Collingwood in a round one MCG blockbuster.