Mercedes driver Nico Rosberg has said that their pre-season pace is not too impressive, despite an ominous display yesterday.

Rosberg's best time at the second pre-season test in Barcelona was just 0.254s slower than Romain Grosjean, but the Lotus man did his lap on super-soft tyres and Rosberg did his on the reportedly slower mediums.

When asked if his pace was good, he told reporters: "If you say so. Not according to our numbers, not so much when looking at times from other days. But we are getting there. Yes we are confident and we think we have a good car."

Mercedes are expected to face stronger competition this season from the likes of Ferrari and Williams, and Rosberg confirmed that they have to watch out.

"We have a great team now, and we are keeping a close eye on the opposition because there have been some quite strong times from other teams. It is not clear cut at the moment, but we are still in a good position," he added.

The new season starts in Australia next month.