While the German manufacturer was buoyed by Lewis Hamilton taking the runner-up spot in the China sprint last weekend, it still endured a challenging main grand prix as it came home behind McLaren and Ferrari again.
But with there being no notable uptrend in its form despite the efforts it has made to better understand its W15, Wolff thinks that it has to lift its game rather than think that glimmers of hope are the reality of where it is at.
Speaking to ServusTV about his reaction to the Chinese GP weekend, Wolff said: “Not satisfied at all. Maybe a small highlight with second place in the sprint race, but the performance is not there.
“We can keep telling ourselves that there were bright spots at the weekend, but we have to take a step.
“We'll bring a bit of something to Miami, where hopefully we can expect something. But today you're just behind the Ferraris and behind [Lando] Norris. Just not good enough."
Mercedes has come into the year upbeat about the progress it has made with its W15, and its early conclusion was the platform was strong but had some weaknesses in high-speed corners.
However, as events have progressed, the team has uncovered more complications with the car, which makes it tricky to find the right sweet spot with the set-up.
Source: Autosport