The German manufacturer endured another difficult weekend in China where the promise of a second place sprint finish with Lewis Hamilton failed to materialize until the main grand prix.
Russell came sixth, Hamilton ninth, as the team was once again searching for answers as to why it could not unlock the potential it believes it has in its W15 car.
And with major changes in direction for both drivers after Saturday’s sprint, failing to improve their potential, the team admits there is still an element of mystery about what is happening.
Team boss Toto Wolff said: “I think the car is a difficult car to set up and a difficult car to drive, and that’s why you have these oscillations in the performance, in my opinion.
“I think where the car is, and where Lewis’ car was, was certainly far from optimal and it’s riding on a knife’s edge.
“So what is it? This is where we are. For Miami we are bringing new elements, and it will be interesting to see how they will perform on the car.
Russell suggests that the way major setup changes over the Chinese weekend didn’t make much of a difference in terms of performance, Mercedes may have to accept that the car delivers everything it’s capable of Right now.
“We had two different setups this weekend, both of which produced very similar lap times and performance,” Russell said.
“So the job has to be back at the factory and ultimately in F1, the more downforce you have, the faster you will go. The set-up is the icing on the cake.
In Russell’s view, Mercedes needs to move away from analysis aimed at finding a perfect setup and return to the more standard approach of focusing on aggressive development and a series of improvements.
“I think there is no miracle solution,” he explained. “We just have to continue to add performance and focus on what’s important, which is in the wind tunnel and in the CFD: just adding downforce. Maybe sometimes it’s that simple.
Russell said so much experimentation and directional changes took place throughout the ground effect era to determine what the team had now, that they may have reached a ceiling on which is possible with his current equipment.
“I think we’ve understood enough so far that we just need to add support,” he explained. “We have changed our philosophy and concepts several times over the past two years.
“My personal view is that whatever concept you’re working on, you just need to have as much support as possible, and you’ll have to deal with the limitations afterwards.
“So yeah, let’s see Miami.” We have some improvements coming to the car. Let’s see what we can do with this.
