Toto Wolff says Mercedes was never able to entice Max Verstappen with the sort of opportunities given to him by Red Bull.

Verstappen is making his Red Bull debut this weekend after his surprise elevation from Toro Rosso last week. Red Bull boss Christian Horner admitted on Thursday the promotion was to tie Verstappen to the team for "multiple years" and ended speculation of a move to Mercedes or Ferrari following his highly impressive rookie season.

While Mercedes was interested in Verstappen in late 2014 the youngster opted for Red Bull's offer of an immediate drive for Toro Rosso the following year. Wolff says the teenager's father Jos had a quick career path in mind for his son.

"He's a really good boy and Jos [Verstappen], he knows things about racing," Wolff said. "I remember seeing Max first time around when he picked up his trophy in 2013 at the FIA awards in Paris when he drove the go-kart on stage and within two years that boy has made himself a name in F1, and for every reason.

"We never had any serious discussions because it was clear that he was in the Red Bull channel. When it mattered for Max we couldn't really give him interesting enough opportunities, Red Bull was giving him the Toro Rosso seat and it was clear that Red Bull needed to give him a Red Bull drive and here we go. Everything has panned out in the way that Jos has planned and that's great."

Wolff thinks Verstappen's performance in qualifying for the Spanish Grand Prix proved that Verstappen has not been elevated too quickly.

"I think the boy in the car did the talking."

Mercedes driver line-up for next season is not set in stone, with Nico Rosberg yet to sign a contract extension to the deal which expires at the end of 2016. However, the championship leader said in Sochi he is relaxed about the situation and has yet to start serious discussions with the team.