Roughead will undergo a posterior cruciate ligament reconstruction on Tuesday and is expected to miss the first half of the season at least.

The four-time premiership star is considered one of the best key forwards in the game, but Brereton sees it differently and believes Hawthorn will be able to cover for the 29-year-old without too much fuss as they embark on their quest for an historic fourth premiership in a row.

"It's a blow, not a huge blow," Brereton told SEN on Tuesday.

"He's the best big small forward in the comp. He actually doesn't play like a key position player and they're pretty well-served for small forwards.

"He goes into the midfield like a small forward does, he crumbs in the forward line like a small forward does and the overhead marks he takes are when he's sort of jumping from behind."

Roughead enjoyed a stellar season in 2015, registering career-highs in disposals, contested possessions, tackles, inside-50s and uncontested possessions as well as kicking 50 goals - his third half-century in a row and sixth of his career.

The former No.2 draft pick has played 231 games and kicked 491 goals for Hawthorn in a decorated career that has also seen him earn two All-Australian nods and win the 2013 Coleman Medal.

Despite being a valuable pinch-hitter in the forward line last season, Ryan Schoenmakers has ruled himself out as Roughead's replacement.

Schoenmakers was used more by coach Alastair Clarkson as a swingman to solve problems across all areas of the ground and the South Australian was keen to continue in the role that cemented his spot in the grand final, rather than become an understudy for the absent Roughead.

"I think my role won't change too much from last year," he told RSN Breakfast.

"Hopefully it will provide an opportunity for some of the younger guys to step up."

Schoenmakers nominated two 21-year-olds as more likely beneficiaries of Roughead's rotten luck.

"Tim O'Brien and James Sicily have had really good pre-seasons," he said.

"Hopefully, one or two of them can push up and play some regular footy and get some games under their belt.

"It will be really exciting (and) it'll be great for the team going forward."

O'Brien has yet to fill Hawthorn's most prestigious guernsey since inheriting the No.23 from Lance Franklin.

The 193cm forward couldn't crack the senior 22 last season but is still well-regarded at Waverley Park and could get his chance in his fourth campaign.

Sicily, a less powerful but trickier player, could find himself stepping up into the AFL line-up should Clarkson opt for a different approach.

Schoenmakers said the balance of the team would change in 2016 with the abolition of the substitute.

"We're wondering how the coaches will go with that, whether (they go for a) taller or smaller player," he said.

"We've all just got to chip in a bit extra and hopefully pick up where we left off from last year."

Either way, Schoenmakers said Roughead's replacement would find big boots to fill.

"He's such a powerful unit. He plays up forward, he can go in the ruck, he's got a lot of great attributes and that's why he's been such a great player for so many years," he said.

"He's going to be tough to replace but we'll do our best."