Hawthorn's Sam Butler has been downed by a suspected broken leg during Box Hill's VFL clash with Sydney on Sunday.

Vision during the third term shows Butler going down with minutes remaining before club doctors ran to his aid.

Play stopped for over 10 minutes, extending the quarter to just shy of an hour as the ambulance was called to Fenjiu Stadium.

Butler was impressive up until the injury, gathering 13 disposals, four marks and three inside 50s.

He had played the last two games in the Hawthorn seniors but was dropped, with the 21-year-old showing real promise in his 19 games across three seasons as the No.23 pick in the 2021 national draft.

Senior coach Sam Mitchell spoke on Butler's horrific leg injury following the loss to Sydney's senior side on Sunday at the MCG.

"He broke his leg in pretty horrific circumstances, so all of our thoughts go out to him ... he's going to have some surgery tomorrow and he'll be out for the season," Mitchell said.

Teammate Chad Wingard made a return to football following his achilles tear in Round 22 last year while Sydney veteran Luke Parker featured for the Swans.