Rosberg fears failure to close wing flap is a problem. They will also have an effect on the racing in the first couple of laps, even though they cannot be used, Nico predicts.
Have the normally ultra cautious FIA missed the possible implications of failure to close or is this, as I'm inclined to conclude, being overstated by Nico; what does anyone else think?
After sampling the adjustable rear wing device for the first time on Tuesday on the first day of pre-season testing Rosberg appreciates it is a complex piece of equipment.
"I tried it and it takes some getting used to," said the German at Valencia.
"You push the button and it lowers at the back, so you feel the car gets lighter, and then you release the button again before braking.
"But you think 'Jeez, what if it hasn't gone back to its original position,' because if it doesn't you are off in a big way.
"It's going to take some adjusting. Because it moves we don't know how quick it resets itself once you release the button again.
"It could be too late and it's not properly attached, so it's still a bit of a concern.
"Once you've got the hang of it you then need to judge whether it distracts you too much when you are in a race situation, with all the things going on.
"We need to keep an open mind on it, and the FIA have said anyway they will do that."
The flap cannot be used on the opening two laps for safety reasons, but Rosberg feels the racing early on will be spiced up anyway as drivers strive to pull a second clear of the car following, or to be within a second of the car in front to execute a pass.
"Things could get a lot more interesting, especially on the first lap when everybody is within a second of one another," added Rosberg.
"It's going to be all over the place, so it can only be good I guess."
Taken from longer piece on Planetf1.com, Feb 1.