HAWTHORN star Will Day has been ruled out of Friday night's semi-final against Port Adelaide, while young midfielder Cam Mackenzie is also expected to miss due to a hamstring injury.

Day has not played since injuring his shoulder against Richmond in round 23 and is yet to resume contact training.

"He's doing a lot of non-contact training at the moment and plenty of conditioning, which is fantastic. We're just not in a position to progress to contact," Hawks medico Peter Burge said.

"We're still in the same situation that we can do a lot of training around it but we can't do contact and if we can't do contact training, we can't play. So that's frustrating."

Mackenzie injured his hamstring at training last week and while the club had initially expected him to be ready for week two of the finals, they have indicated he'll also be unavailable for the trip to Adelaide.

"He's got a really low-grade hamstring strain so initially on scan, we thought this could turn around in a week. But it's probably going to be more like two weeks at this stage," Burge said of Mackenzie.

"He's already back running, he's running at 50 per cent speed. We just haven't got enough sessions this week for him to turn it around for this weekend. He'll keep progressing, we're fairly confident this will progress quickly but at the same time, we'll be really smart with what we do and how we progress."

On Sunday, defender Sam Frost was ruled out for the rest of the season due to a serious foot injury.

"He has a stress fracture in his foot. We have to respect it, we can't push through it, we can’t do anything else to keep him going unfortunately. It has to be offloaded," Burge said.

"He's in a moonboot at the moment and even in the moonboot, he's quite sore and he can't take much weight. So unfortunately, his season is done."