Red Bull principal Christian Horner has made it clear that the Toro Rosso junior squad isn't expected to play the part of test team for the rest of the 2018 season.
Speculation about Toro Rosso's role was sparked by comments from motorsports consultant Helmut Marko. He said Red Bull wouldn't object if engine providers Honda pursued a programme of upgrades, even if this incurs big grid penalties.
Each driver is only supposed to use three sets of power unit components during the year. Both Pierre Gasly and Brendon Hartley have already exceeded the limit ahead of the midway point of the season.
Encouraging Honda to introduce more upgrades despite the threat or penalties would potentially benefit Red Bull in the future, which has announced it will switch to Honda power units in 2019.
But Horner played down this likelihood on Wednesday in comments to Motorsport.com
"I don't think we'll be pushing them [Honda] to sacrifice Toro Rosso," he said.
"Obviously there are opportunities to learn for the benefit of the group, which ultimately Toro Rosso will benefit from as well.
"That's obviously something that remains open," he added.
"But of course Toro Rosso has their own fight with the constructors they're competing with, that obviously has significant value to them."
Toro Rosso has failed to score a single point since Monaco. It has slipped to eighth in the constructors championship standings as a result.
The team currently has less than half the points of the team in front in seventh place, and is just three points clear of Sauber in ninth.
Despite the introduction of a new-specification Honda engine at Montreal, Gasly described Honda's one-second-per-lap deficit to Mercedes and Ferrari at the most recent race at Silverstone as "crazy".
But Horner insisted that the Honda's performance was on a par with that of Red Bull's current engine partners Renault.
"You can see that the performance of the engine is pretty close to where we currently are with our current supplier," he said.
"Of course, Toro Rosso have been running varying amounts of downforce at the past couple of venues.
Horner added that in his view, Honda was "on the right trajectory" with its development programme.
"They seem to have the right goals and targets," he said. "We're looking forward to working with them in a much more collaborative manner as we move into this new relationship."