Red Bull boss Christian Horner thinks Toro Rosso's strong form shown at the Australian Grand Prix will be maintained at least for the first half of the season.
Max Verstappen and Carlos Sainz caused a stir in Melbourne as they fought it out with bigger teams for a top five finish, before a strategy call and time lost behind traffic left them further down the order.
But with the STR11 having shown itself very quick – especially in qualifying trim – Horner thinks that they will be a big threat.
"The Toro Rosso cars you can see are fast, particularly over a single lap," explained Horner.
"Lewis [Hamilton] couldn't pass a Toro Rosso on the straight, he passed us a little easier than he did those guys.
"You can see they've got a competitive car, and we expect them to be, as predicted pre-season, quick, certainly in the first half of the year before upgrades start to kick in."
Toro Rosso is using 2015 Ferrari engines, and fully expects to fall behind rivals as they start to enjoy current year power unit development.
For the Bahrain Grand Prix, Horner believes that Ferrari's engine advantage over Renault will be another boost to Toro Rosso.
"Bahrain, there is a slight more emphasis on power than there is [in Australia], so that's not going to play to our advantage," he said.
"But we've always run reasonably competitive in Bahrain, in other areas of the circuit. So… I hope that we take this momentum into that event."