Red Bull boss Christian Horner has stated that his team will not be supplying McLaren with engines in light of Rob Marshall's departure to the Woking-based outfit.
Last month, it was announced that McLaren had signed Masrhall to become their technical director of engineering and design, starting in January.
There had been speculation that Marshall's move may be linked to an engine supply deal, with McLaren supposedly using the new Ford-backed Red Bull Powertrains PU in 2026.
Despite both teams admitting there were talks between CEO Zak Brown and Horner, the latter has moved to quash talks of an engine supply deal.
In February, it was announced that Red Bull and Ford will team up from 2026 onwards ahead of brand new regulations in Formula 1.
The American manufacturers are making their comeback to the sport nearly 20 years after leaving, with engines set to become greener in the sport's attempt to limit their carbon outputs.
Ford have agreed a deal with Red Bull and are also set to be the suppliers to their sister team AlphaTauri.
McLaren will not be part of the equation though with Horner admitting it would potentially create too much work.
He added: “Our plan at the moment is to supply two teams because we don't want to overstretch ourselves in the first year, so. And of course, those teams are likely to be the two Red Bull-owned teams.”