However, the Herald on Sunday understands that Tuivasa-Sheck and Harris have made the decision to put club before country themselves, despite both coming through Friday night's win over the Cowboys unscathed.
Tuivasa-Sheck made a successful return from an ankle injury that kept him out of last week's win over the Sea Eagles, scoring a brilliant individual try and having a hand in two others, as the Warriors claimed a rare away win in Townsville.
The 25-year-old fullback's long-term health is vital to the Warriors' hopes of making the finals for the first time since 2011, and he and Harris have made the call to stay home and rest ahead of their next game against the Cronulla Sharks on Friday, June 29.
Warriors coach Stephen Kearney has previously said any players who turn out for the Kiwis would sit out the match against the Sharks, due to concerns over player welfare and recovery.
The Kiwis are due to return to New Zealand on Tuesday, June 26, just three days before the round 16 match at Mt Smart Stadium.
The quartet's unavailability further depletes the Kiwis stocks after former test captain Simon Mannering and front row pair Russell Packer and Ben Matulino this week announced their retirement from test football.
Injuries to fellow former Kiwis captains Benji Marshall (calf), Jesse Bromwich (hamstring) and Kieran Foran (toe) and a hamstring injury to Raiders wing Jordan Rapana have robbed the side of further class and experience.
It remains to be seen whether any further withdrawals impact on Maguire's plans for his first test in charge since replacing David Kidwell.
Sea Eagles prop Martin Taupau has expressed concerns about playing for the Kiwis and potentially being unavailable to turn out for Manly in their clash against Penrith on June 30.
Sydney Roosters front rower Jared Waerea-Hargreaves, in good form during the smashing of Penrith on Friday night, was also on the fence about whether he would be available for selection, with the Tricolours scheduled to play the Storm in Adelaide five days after the Denver test.
To get the day's top sports stories in your inbox, sign up to our newsletter here