The Kiwi comes in at blind-side flanker in a back row which sees Ollie Leatherbarrow slide across to No.8 – the starting XV otherwise unchanged from the one which played last week against Bath.
Head coach Alan Dickens is relishing the prospect of tackling the Bears in front of a bumper festive crowd at Ashton Gate, saying: “The Christmas games are always fantastic atmospheres, and something to get really excited about.
“It’s a great time of year for people to come out and watch sport, and we’re all looking forward to what should be a great contest.”
Beaten by champions Bath Rugby last time out, the Newcastle boss said: “We did a lot of good things in the first half but fell away in the second, and we just weren’t good enough.
“Bath are the champions, and are top of the league with the fantastic squad they’ve got. They were clinical in how they took their chances, but the overriding feeling from ourselves was disappointment that we didn’t build on a promising start.
“When you allow good teams into your 22 you’re inviting danger, and against a quality side like Bristol we know we can’t do that.
“They had a big win against Harlequins last week and you have to respect what they bring to the game, but on the same token we’re just focusing on ourselves.
“We’re working on the detail of our own game, and if we can get that right then we’re in with a shout.”
Newcastle Red Bulls team v Bristol Bears (Saturday, 3pm, Ashton Gate, live on Discovery+)
15 Ethan Grayson, 14 Oli Spencer, 13 Alex Hearle, 12 Sammy Arnold, 11 Elliott Obatoyinbo, 10 Brett Connon, 9 Simón Benítez Cruz; 1 Adam Brocklebank, 2 George McGuigan (captain), 3 Murray McCallum, 4 Oscar Usher, 5 Seb de Chaves, 6 Tom Gordon, 7 Tom Christie, 8 Ollie Leatherbarrow.
Replacements: 16 Ollie Fletcher, 17 Connor Hancock, 18 Richard Palframan, 19 Finn Baker, 20 Amanaki Mafi, 21 James Elliott, 22 Boeta Chamberlain, 23 Cameron Hutchison.
Not available for selection: Rhys Beeckmans, Eduardo Bello, Freddie Clarke, Joe Davis, Luan de Bruin, Connor Doherty, Hame Faiva, Joel Grayson, Callum Hancock, John Hawkins, Jamie Hodgson, Elvis Kitenge-Fuki, Fergus Lee-Warner, Freddie Lockwood, Christian Wade, Liam Williams.
Referee: George Selwood.