Carlos Sainz's car was fitted with the new design at Mugello for a brief run at the start of FP1.
The nose is very similar to the design pioneered by Mercedes, with a narrow main structure, and narrow under nose pillars. The cape is also positioned higher.
The nose change has forced McLaren to conduct a new crash test, and it will have to make a decision about which direction it wants to go with this area of the car before a September 30 deadline that freezes major car parts.
McLaren team principal Andreas Seidl suggested that the nose had delivered some promising figures in the wind tunnel, which it now needed to see carried over to the race track.
"We simply want to gather some data because we found a good direction there in the wind tunnel," he said "It's something we want to confirm on track first, before we then make decisions on if that's something we want to bring to the track later in the year."
McLaren MCL35 nose detail