Fernando Alonso is sporting a bandage around his right knee in the Valencia paddock.
He played down the injury.
"It’s nothing, I had a fall in cycling and it will heal but for now it’s just a bit swollen. It’s nothing important," the Ferrari driver is quoted by Spanish sports daily AS.
Also firing on less than the full eight cylinders on Friday was Marussia’s Timo Glock, suffering from a stomach bug and running a shorter programme.
"For a time I have to say I was feeling quite unwell," said the German. "Back in the car I have felt a little better and I am hopeful that I am on the mend."