Following Pierre Gasly's crash on the penultimate day of testing, Red Bull, and in particular Max Verstappen, was unable to stretch the legs of the RB15 with a qualifying sim.
However, while the Austrian team continues to talk in glowing terms of its new engine partner, Verstappen, reflecting on the test, said in Barcelona that some things could have been better.
Asked today what those things might have been, the youngster was giving nothing away.
"Some things," he snapped. "I cannot go into detail, can I? No, I can't.
"We had a good winter test, not too many issues,” he added, "and I was just very happy about how everybody was working together, which I think is very important, and a good start.
"Of course, integrating the new engine into the chassis but it didn't seem like it was giving us problems, so very happy about that.
"I could do most of my running, so that was very positive but in terms of performance, I think it's a bit difficult to judge at the moment where we exactly are. I didn't have any time to do performance runs, or whatever but yeah, we're happy with what we did.
"Of course, I think it can always be better, I think everybody has that thoughts. I guess here - but not only here in Melbourne - we'll find out throughout the beginning of the season where we will stand."
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