Hawthorn defender Grant Birchall is set to miss around four weeks after fracturing his jaw in the Hawks' loss to Adelaide on Saturday.

Hawthorn football manager Jason Burt confirmed the news on Sunday, after Birchall suffered the injury in a mid-air collision with Adelaide forward Tom Lynch.

"Grant had scans last night which unfortunately confirmed a fracture of the jaw," Burt told the club's website on Sunday.

"He will have surgery today and we will have a better idea on his timeline for return following that. At this stage, it is likely to be somewhere between three to four weeks.

"It's a disappointing result for Grant so early in the season, but he'll be doing everything he can to return to the field as soon as possible."