22-year-old Willock enjoyed a stunning three and a half-month loan stint on Tyneside at the back-end of the 2020/21 campaign, netting eight times in just 14 appearances to help steer United away from the Premier League danger-zone.
The Londoner re-joined the Magpies on a permanent basis a week ago, leaving boyhood club Arsenal for an undisclosed fee and putting pen to paper on a long-term deal.
And his inclusion in Saturday's squad is made all the more important for Steve Bruce after the Magpies' head coach revealed that Shelvey - who sat out a large chunk of United’s pre-season campaign - is set for another spell on the sidelines.
"Jonjo won't make it. He had a calf injury during pre-season and it's his other one now - which is Sod's law," he said.
"If I'm being brutally honest, I'd have liked (Joe) to have a few more minutes under his belt in terms of playing in pre-season but, thankfully, he's a naturally fit young man. It's good to have him around and he'll be in the squad, that's for sure.
"We're delighted we've got him - he was our main target all summer because of what he gave us when he came here. He improved us immensely with his goals from midfield, so let's hope he can carry that on tomorrow."
Shelvey won't be the only senior absentee at Villa Park on Saturday, with goalkeeping duo Martin Dúbravka (foot) and Karl Darlow (illness) unavailable for the foreseeable.
"We've got a problem with the goalkeeping position at the moment, where we're toying with the idea of naming four ('keepers) in the (Premier League) squad - which is basically unheard of - because of the problems we’ve got with Karl and the problems we've got with Dúbravka," said Bruce. "It's a big concern to us.
"The injury Martin's had, unfortunately, has become infected, which is going to set him back another few weeks, and Karl has still not overcome the Covid situation he found himself in. They're still a long way off, so Freddie (Woodman) will play again."
United lost 4-2 to West Ham on the opening day of the campaign - despite leading twice at St. James' Park - and are gearing up to face a Villa side who shipped three goals themselves last weekend, Bruce's former club going down to Premier League new boys Watford in a high-scoring encounter of their own.
"First half, I thought it was a smashing game of football between two very good teams," United's head coach said of his side's curtain-raiser. "Unfortunately, second half, we got caught, and what we can't do is chase the game in the way we were trying to. We left ourselves open and vulnerable, so that has to improve.
"We must defend better. I'm not just blaming that on the back three - we must defend better (as a team). We know we're a threat going forward, so if we can get that part right on Saturday and defend well, then we've got a chance."
