Antonio Felix da Costa: Red Bull reserve in 2014

Da Costa has already performed the reserve role at several races last season, deputising for Buemi who also races for Toyota in the World Endurance Championship.

The Portuguese, 22, finished third in the 2013 Formula Renault 3.5 championship and had been seen as the man to replace Red Bull-bound Daniel Ricciardo at Toro Rosso. However, they instead promoted GP3 champion Daniil Kvyat to take the seat.

Even so, da Costa will race next season as part of BMW's DTM programme. He has taken part in two young driver tests for Red Bull before and can expect time in the cockpit in 2014, with plans to run reserves in first practice at races as well as the return of in-season testing.

Sportscar commitments permitting, meanwhile, Buemi will return to the role for a third season. The 25-year-old Swiss raced for Toro Rosso between 2009 and 2011.

Red Bull Team Principal Christian Horner said: "It's great to be able to announce the signing of Sebastien and Antonio for 2014. Next year sees the biggest change to the Formula One regulations for some time and the return of multiple in-season tests. To therefore be able to call on two such capable drivers is of huge benefit to the team.

"In Sebastien we have a great resource, a driver with extensive grand prix experience and that will be invaluable. Antonio, on the other hand, is an up-and-coming talent with whom we already have a good working relationship. I'm sure that his contribution will be just as important during what is sure to be an intensely busy season."