Grant Birchall is expected to miss the first half of the 2018 season, with the veteran defender requiring further surgery to his injured knee.

According to GM-Football Graham Wright, Birchall was making strong progress before pulling up sore following a training session this week.

“Grant was progressing really well and had been coping with the training loads,” Wright said.

“His training was solid this week, but unfortunately he experienced some swelling and upon investigation, we found some cartilage damage.

“We decided the best course of action was to have some minor surgery early next week.

“It’s disappointing for Birch, particularly after a really tough year in 2017, but we’re confident we’ll see him back out on the park around the middle of the season.”

Will Langford is also facing a delayed start to his 2018 campaign after breaking his hand during a training session this week.

The setback comes as Langford was nearing a return to the game, having recovered from a finger tendon injury on the opposite hand sustained during the club’s pre-season camp in December.

He went in for surgery on Wednesday to have screws and a plate inserted, and is expected to be sidelined for 3-4 weeks.

Read: Hawthorn's season preview