"They were both very close this week. It just would have been pushing the envelope a little bit to play them," Hardwick said.
"Both are obviously very important players – our best defender and our best run-and-carry player. So they'll make a difference, but we've also got to realise they haven't played for five weeks, so it's going to take some time."
Hardwick acknowledged playing without the duo, plus ruckman Ivan Maric, had meant the club had taken on last year's premiers without three of its best six players.
But he did suggest it was more than just personnel issues that had caused the Tigers slip to just two wins from their opening six games.
"We're not playing anywhere near as fluent as what we did last year, there's no doubt about that," he said.
"We know that, we're trying to rectify that. We've got to continue to work ... the players, the coaches, the lot of us."
Having beaten the Hawks by large margins in their previous two encounters, Hardwick thought his opponents had came to the game more prepared to run.
"They probably learned a couple of lessons from us last time how we played them and they just got outside us really easily," he said.
Ty Vickery could return to the forward line after three goals in the VFL on Anzac Day, while the club will consider blooding its first draft pick from last year, Ben Lennon, against the Cats next Sunday.
"[Lennon] will be [close] after tonight's result," Hardwick said.
"He was an emergency this week. He's a guy who uses the ball well, he marks it well, and he reminds a little bit of [Geelong's Andrew] Mackie. He can play tall, small. He'll be thereabouts this week."