Max Verstappen might have been fifth fastest on Friday afternoon, but an issue during FP2 deprived him of valuable running time.
The Red Bull ran only 15 laps in the session. He missed out on much of the last hour of track time after pulling over at pit entry and reporting a loss of power.
"We think it was a fuel pressure issue," he reported. "A shame. Again not a long run but that's how it is.
"We ended up stopping sooner than planned due to the problem," he continued. "It prevented us doing a long run
"Luckily Daniel did one so we at least have some data to look into for Sunday."
Even allowing for the late technical glitch, Verstappen was still disappointed to be over a second slower than the Ferraris of Sebastian Vettel and Kimi Raikkonen.
"This track is not one of our favourites," he admitted. "We knew coming here it was going to be a tough weekend. We will just try to make the best of it.
"The gap to Mercedes and Ferrari looks bigger here because of the long straight," he explained. "We are down on power and downforce which makes not only the straights but also the corners tricky.
"I think qualifying will be interesting due to the challenge of warming the tyres up," he added. "It's the same for everyone so putting in one perfect lap won't be easy.
"Realistically fifth and sixth is our aim for Sunday," he concluded with a sigh. "We'll just make the best of it."
GALLERY: All the pictures from Friday in Sochi
Keep up to date with all the F1 news via Facebook and Twitter
