Toro Rosso technical director James Key admits the team's 2016 challenger has been compromised by the late confirmation of its Ferrari engine supply.
Toro Rosso was left with an uncertain wait at the tail end of 2015 as it indirectly suffered from Red Bull's fall-out with Renault, with the parent company threatening to quit the sport on numerous occasions. While Red Bull eventually went full circle and returned to Renault engines for this year, albeit branded as Tag Heuer, Toro Rosso settled for a supply of year-old Ferrari engines.
With installation of the power unit an important part of chassis development Key says the timing of the agreement, which was confirmed in December, has delayed the team's plans.
Asked by Sky Sports F1 if the delay had compromised Toro Rosso, Key replied: "Yes and no, because when you've got a tricky engine situation it's always a compromise. There is a compromise because you've really got to be optimising your car around what is an incredibly complicated installation of these power units. Back in March is when you're really getting to grips with what you're trying to do.
"So it does compromise from a technical viewpoint. In terms of what the team is doing, I don't think it makes the slightest bit of difference. You simply shuffle plans around accordingly.
"We've got various stages of planning, there are some really good guys to work on all this stuff, so we've got a lot of very competent production guys and designers who are working hard to make sure that we're in the best shape possible. You'd never want it because it is a massive distraction and it does compromise your car, but it's surprising what you can do when you're faced with uncertainty."
Toro Rosso demonstrated the strength of the STR10 chassis by locking out the third row in Spain last year and Key thinks the team can still build on that in 2016 despite the compromise.
"For sure we can build because we learnt a massive amount and made a huge step from the STR9 car. Most of it we understand why [we improved], there are areas that perhaps surprised us a bit too and we made a bigger step than expected.
"So you build on that. In some cars it's reinventing stuff to release more of the potential, in other cases it's taking a philosophy that seems sound and pushing it to the next step where you need a redesign to do that, because in-season it's not possible."