For once, Will Day feeling like he'd been hit by a truck was a good thing for Hawthorn.

The injury-plagued star midfielder came through his first game of the season without any problems, and he will finally make an AFL comeback against St Kilda on Friday night.

Veteran forward Jack Gunston also returns in another big boost for the fourth-placed Hawks.

Day, one of Hawthorn's most important players, is yet to play senior football this season because of a dislocated shoulder. He was also restricted to six AFL matches last season because of injury.

The 24-year-old returned through Box Hill in the VFL last week, delighting the Hawks.

"He's excited to be back playing footy," coach Sam Mitchell said.

"Even the soreness post-game, he said that feeling - 'in a sense, I missed it'.

"That feeling's horrible, you wake up the morning after a game and you feel like you've been run over by a truck. He hadn't felt that for a while, but he said 'that hit me with the full force', so I was pleased to have him back playing.

"(But) in all of the parts that matter, he's fine."

While Day's return will bolster Hawthorn, Mitchell said he is not the brown and gold Messiah.

"Adding talent back into your group is always important, but we would like to think we don't rely on individual players too much," he said.

"It's a bit of a risky way to plan your strategy. So he's a very good player, and we love having him out there.

"Can we not win games without Will Day? Well, of course we can. And are we better with him in? Of course we are.

"So he's a player who's going to be important for us when the right time comes."

After their excellent win over Adelaide last week, the Hawks come up against Ross Lyon's Saints at Marvel Stadium - always a fraught assignment.

"It doesn't feel like there are any easy weeks in the AFL," Mitchell said.

"If you look at the results of last week, I don't know how everyone's tipping is going, but it's quite a difficult year.

"We see the Saints, they're in front in the last quarter against Fremantle in Perth. They're playing some really good footy.

"Ross's sides are historically really difficult to play against. The potency at the moment with the way they're playing has been first-class."

St Kilda lost key defender Dougal Howard to a calf injury and will be managing Liam Stocker this week.

Isaac Keeler and Alix Tauru come in for the Saints, who slipped to a 5-6 record following last week's 30-point loss to the Dockers.

Hawthorn dropped Bodie Ryan and Finn Maginness to make room for Day and Gunston.