Norris: It's not just me and Oscar, there's Max and Ferrari

McLaren's top two are separated by three points in the Championship standings after eight of 24 races and the champions have won six times this year -- Piastri with four to Norris's two.

Norris led for the first time after winning the F1 season-opener in Melbourne before ceding the advantage to Piastri in round five in Saudi Arabia but closed the gap again by winning in Monaco last Sunday. Red Bull's Verstappen, the four-time world champion, has won twice and is third, 25 points behind Piastri.

Norris told reporters in Spain: "I think mathematically, probably the whole grid can win the championship. I think there's plenty of opportunities. Max can still win, I think Ferrari. I expect them to get better into the season.

"Max has been on the podium several times, he's won races, he beat us in Imola fair and square because he was quicker. I don't know what possibly makes you think that it's only between us (McLaren drivers)," added Norris.

Spain is a favourite track for Verstappen, the place where he won for the first time in 2016, and Piastri expected the Dutch driver to go well again on Sunday: "I don't think he can be counted out."

"The gap is not very large at the moment and they've genuinely been competitive at a decent number of circuits now. Of course there's been weekends where we've been stronger but I think they've been developing their car, they've been finding more performance. So I think at this point, Max is definitely still in the title race," the Australian told reporters.

Verstappen has won the last three Spanish Grands Prix, and four in total, and has been on the podium seven times in a row at the circuit but he was not bigging up his prospects on Thursday: "For me it doesn't really feel like a fight, to be honest.

"I just try to do my best, have a bit of fun out there. With some races we are really off the pace, which is not enjoyable. But the fighting spirit is still there. That is also never disappearing," insisted Verstappen.

Formula 1 also has a front wing rule change coming into effect this weekend, with the governing FIA carrying out more stringent stiffness tests.

McLaren say they do not expect to be affected but others are taking a wait-and-see approach, with Ferrari even speaking of a potential game-changer. However, Norris predicts differently: "There are tweaks here and there, but nothing that will change how we have to do it."