Sauber boss Monisha Kaltenborn has praised the performance of new drivers Felipe Nasr and Marcus Ericsson so far this season.

The Swiss constructor decided to replace Esteban Gutierrez and Adrian Sutil following a disappointing 2014, which saw the team fail to score a point.

However, both Nasr and Ericsson have been in contention for top-10 finishes from the start, which Kaltenborn believes has given Sauber a boost.

"If you look at how close they are to each other, one is faster one time then, next time, it's the other one, so it's very well balanced," Kaltenborn is quoted by Crash.net as saying.

"That shows you what level they are [at], what level the car is and it just depends on who has the better day as to who is ahead.

"The car is competitive, the drivers have done a fantastic job – both of them – so that gives us a lot of optimism."

Sauber are currently fifth in the Constructors' Championship.