YOUNG Hawthorn key forward Calsher Dear is facing a delayed start to 2025 after scans revealed a bone stress reaction in his lower back this week.

The 19-year-old produced a dazzling first season in the AFL, playing 17 games after making his debut against the Western Bulldogs in round eight, including both finals in September.

Hawthorn don't yet have a timeline for the father-son recruit and won't get a clearer picture of a return date until he has a secondary scan at the end of January.

With Mitch Lewis still recovering from a knee reconstruction and not expected to be available until midway through 2025, Dear has a key role to play next year if he can get his body right.

In good news for the teenager, he has also put pen to paper on a one-year extension that will see him contracted until the end of 2026, adding a third season to the initial two-year deal he signed last November when Hawthorn selected him at pick No.56.

Under the new Collective Bargaining Agreement, players selected beyond pick No.20 receive two-year contracts. The third season is on a set base, plus bonuses based on games played and achievements across the player's first two seasons.

Dear finished with 25 majors in his first season in the AFL, including 3.4 in front of 97,828 people in the elimination final win over the Western Bulldogs in September.

Veteran forward Jack Gunston has been impressive on the track across the first block of the pre-season and will play an important role for Sam Mitchell's side next year, especially in the early phase of the season if Dear is unavailable.

Wingman Massimo D'Ambrosio missed the final week of training ahead of the Christmas break after having his appendix removed.

D'Ambrosio was unable to train this week while the wound healed but is expected to return to full training when the Hawks report back for training on January 9.

The 21-year-old was included in the All-Australian squad in 2024 in his first season after moving from Essendon in search of greater opportunity.