Red Bull advisor Helmut Marko has put the pressure on Toro Rosso pair Sebastien Buemi and Jaime Alguersuari by insisting that the team 'isn't a boarding school'.

The pair have been retained by the team for the new season but Toro Rosso has signed Daniel Ricciardo as test and reserve driver after an impressive show in testing in Abu Dhabi last year - with the Australian set to drive in Friday practice during the year ahead.

With British F3 title winner Jean-Eric Vergne also highly rated by Red Bull, Buemi and Alguersuari are under pressure to perform and Marko said that Ricciardo and Vergne would be given a chance if the results don't arrive for the two race drivers.

"In Ricciardo and Vergne we have two outstanding talents," he told Auto Motor und Sport. "Buemi and Alguersuari know that their job is not a pillow, and we are not a boarding school.

"Buemi's services last year were not what we expected of him. Alguersuari has developed, but is it enough?"

Marko added that Vergne in particular had a fighting spirit that exceeded the other three drivers.

"If our four drivers went side by side into a corner," he said, "I guarantee Vergne would come out the other side first."