Two Junior Wallabies in No.8 Will Harris and inside centre Joey Walton will make their Waratahs debut in Brisbane, and uncapped forwards Tom Horton and Tiaan Tauakipulu and five-eighth Ben Donaldson have been named on the bench.

Youth and inexperience sometimes leads to inconsistency and mistakes, but Penney won't be using that as an excuse for his youngsters.

"Standards are set, we can't accept mediocrity," Penney said.

"They're picked because they are good enough and the expectation is that they will deliver on that, so we won't be reducing our expectations because of the age."

Penney said the Waratahs energy levels after they returned to training were led by the youngsters.

"They created a bit of a wave and everybody got in behind them and rode the crest of that wave. It's a credit to them," Penney said.

"The time is right to give them an opportunity and let them unleash themselves."

Injuries have ruled out Lalakai Foketi and Wallabies Karmichael Hunt, Jake Gordon and Tom Robertson, but the run-on side includes four Test forwards and Jack Maddocks at fullback.

Wallabies forwards Jack Dempsey and Tetera Faulkner have been named on the bench, with Harris getting a starting nod ahead of Dempsey.

"He (Harris) has got a great work rate and is a very good decision-maker and is someone we think will establish himself into this level of rugby quite quickly," Penney said.

"He's got good intelligence, good emotional intelligence so he connects well with the group and he has got leadership potential, so there's a lot of qualities to like about Will."

With Foketi and Hunt out and Kurtley Beale having left, Walton gets a chance to shine in the centres.

"Joe is an Energizer Bunny, he's got a lot of really good traits that midfielders need," Penney said.

"An unrelenting work ethic, great passion and desire to win and he's got a skillset that provides us with a run-kick-pass option."

Penney praised forward veterans Rob Simmons and Michael Hooper and foreshadowed a terrific battle up front with a rugged Reds pack.

"It's going to be a really good challenge a true State of Origin," he said.

Waratahs: Jack Maddocks, James Ramm, Alex Newsome, Joey Walton, Mark Nawaqanitawase, Will Harrison, Mitch Short, Will Harris, Michael Hooper, Lachlan Swinton, Rob Simmons (capt), Ned Hanigan, Harry Johnson-Holmes, Robbie Abel, Angus Bell

Replacements: Tom Horton, Tetera Faulkner, Tiaan Tauakipulu Tom Staniforth, Jack Dempsey, Michael McDonald, Ben Donaldson, Tepai Moeroa

Australian Associated Press