Red Bull insist Toro Rosso will not be "sacrificed" for the remainder of 2018 as Honda looks to develop the power unit which both teams will use next season. Red Bull chief Dr Helmut Marko suggested earlier this week that Toro Rosso may take more engine penalties for the remainder of this year in order to test 2019 parts on-track.
After initially impressing in the early races of the season, Gasly's fourth-place finish in Bahrain especially, Toro Rosso are eighth in the constructors' championship, but have a rapidly improving Sauber team just three points below them.
And Red Bull team principal Christian Horner says the sister team's championship ambitions remain a priority.
Horner told Motorsport: "I don't think we'll be pushing them [Honda] to sacrifice Toro Rosso.
"But 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, but of course Toro Rosso have got their own fight with the constructors they're competing with, that obviously has significant value to them."
Gasly recently said "question marks" remained on the updated Honda PU that was introduced for the Canadian Grand Prix and Toro Rosso have not scored a point in the four races since taking the upgrade.
"From what we saw, certainly the last couple of samples – Austria and Silverstone – you can see that the performance of the engine is pretty close to where we currently are with our current supplier," said Horner.
"Of course, Toro Rosso have been running varying amounts of downforce at the past couple of venues.
"It feels like Honda are on the right trajectory. They seem to have the right goals and targets, and we're looking forward to working with them in a much more collaborative manner as we move into this new relationship."