Harding, who was placed on IR Wednesday in order to make an adjustment to his medication for multiple sclerosis, leads the NHL with a 1.51 goals-against average and is second with a .939 save percentage. He is tied for second with 18 wins, two behind Penguins goalie Marc-Andre Fleury.
Wild coach Mike Yeo said Minnesota was aware of Harding's condition for a "couple days."
"We've known that this was coming and we didn't feel any need to talk about it, we didn't want any distraction before our Vancouver game," Yeo said. "It's something that is a minor adjustment that we have to make. He feels great, he wants to make sure that everyone understands that.
"This is just a minor thing that he'll be ready to rejoin us right after Christmas."
Yeo said he thinks this is an opportunity for Backstrom to regain his form.
"The way [Harding] has gone and the way things have been going for [Backstrom], he's known that when he comes in, he's kind of known that when he comes in he gets this one game and everything is riding on this," Yeo said. "I think he understands that this is an opportunity for him to play a few games and get feeling good. We're really confident in him."
Pittsburgh did not have a morning skate after playing against the New York Rangers at Madison Square Garden on Wednesday, but it is well known Neal, who has 10 goals and 20 points in 16 games, will return after serving a five-game suspension.
The Penguins won each of those five games and have won 10 of their past 11, but are looking forward to welcoming back Neal as well as other players who are injured or suspended.
But Penguins coach Dan Bylsma said Pittsburgh is confident with the group it has in the meantime.
"If everyone got healthy tomorrow [Thursday], you're talking about a substantial number of guys getting back in the lineup," Penguins coach Dan Bylsma said after their game Wednesday. "I don't think how we play, I don't think expectations, I don't think style of play, game plan really changes by getting one or two players back or getting everybody back for that matter.
"I think that's the good things about having these guys [call-ups] come in and play. They know how to play and they know the expectation."
Here are the expected lineups for the Wild and Penguins:
Scratched: Brian Gibbons
Suspended: Deryk Engelland
Injured: Evgeni Malkin (lower body), Kris Letang (upper body), Brooks Orpik (head), Andrew Ebbett (ankle), Beau Bennett (wrist), Tanner Glass (hand), Paul Martin (leg), Rob Scuderi (ankle), Jayson Megna (lower body), Tomas Vokoun (pelvis)