Hawthorn have ruled out gun midfielder Will Day from returning for Friday's semi-final against Port Adelaide.

The 23-year-old has not played since Round 23 due to an SC joint collarbone injury that has significantly limited his training workloads over the past week.

While Day has been able to increase his running abilities, the reigning Peter Crimmins Medal winner hasn't managed to return to full fitness and strength training.

The Hawks made an early call ahead of their September return last week to put a line through Day's playing prospects for their elimination final against the Western Bulldogs, and a similar decision has been handed down ahead of the club's upcoming semi-final trip to South Australia.

The Hawks have ruled Day out of playing against the Power four days from the interstate final.

โ€œHe's doing a lot of non-contact training at the moment and plenty of conditioning, which is fantastic," Hawks high performance manager Peter Burge said in a club update.

"We're just not in a position to progress to contact, so the joint stability, the integrity of that needs to have improved and we're not at a level where it has, and that's a really important part of making this decision to progress to contact, the stability around the SC Joint.

"So at this stage, 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. But Will is a professional, he's doing everything he can and he's certainly working really, really hard on his game. If you were out here today, he's doing some non-contact football drills, he looks fantastic, but we're just not in a position to progress yet, unfortunately.โ€

The decision will likely mean coach Sam Mitchell will be forced into just one change for Friday night's affair, with key defender Sam Frost's season confirmed to be over due to a foot injury.

The Hawks are set to weigh up one of Ethan Phillips or Jai Serong to replace Frost, with both backmen coming off strong seasons in the VFL for Box Hill.

Young midfielder Cameron Mackenzie is unlikely to return from a low-grade hamstring strain suffered at training last Wednesday, with his absence - coupled with Day's - likely leaving Finn Maginness and Josh Ward in Mitchell's lineup to face the Power.

"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," Burge said of Mackenzie.

"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.โ€

The Hawks will confirm their 23-man side on Thursday at 6:20pm (AEST), while Mitchell's final lineup will be locked in an hour prior to Friday's 7:40pm opening bounce.

A win over the Power would see the Hawks progress to the penultimate week of the season, with minor premiers Sydney awaiting. Day could be fit in time for that match, which would fall on Friday, September 20.