Aldo Costa has played down fears Mercedes' 2019 campaign is starting off with an engine problem.
Team boss Toto Wolff said recently that there had been initial problems with next year's engine on the test bench.
"I think it was a bit misunderstood," Costa, a Mercedes technical boss, told La Gazzetta dello Sport.
"When you put a new engine with new concepts on the bench, there may be something that doesn't work. But it's nothing dramatic," he insisted.
Nonetheless, Costa is expecting Ferrari to challenge hard in 2019.
"Ferrari will obviously be there to fight with us, and I am also expecting Red Bull, considering that they always speak good things about the new Honda engine," he said.
However, Costa said he is not sure Red Bull's Max Verstappen is ready to fight for a title.
"He is a talent, he is fast, but he still has to improve his consistency in order to become the winning weapon that Hamilton is," he said.
"Certainly for us it was not a perfect year. We struggled to understand the tyres and in this way Red Bull was better than us. Even our reliability was good but not exceptional," added Costa.
