What happened: Valtteri Bottas drove into the pits before the start of the São Paulo Grand Prix. Sky's pre-race cameras showed what appeared to be a stuck wheel nut on his right-rear.

Why it matters: It follows a barrier crash at the Mexico City Grand Prix a week earlier, from which he climbed out unaided.

What to watch: Watch whether the crew frees the wheel in time and where Bottas rejoins the field.