Alonso: next three races are crucial

"The next three races you need to be there, you need to be on the podium in all three races," the Spaniard told reporters at the Monaco Grand Prix on Wednesday.

"If not, you start to lose too many points.

"At the moment we are four drivers fighting for everything but if one of them has two or three bad results, then maybe it's a little bit too far in terms of championship points," added the McLaren driver.

Briton Lewis Hamilton, Alonso's 22-year-old rookie teammate, leads the championship with 30 points after four podium finishes in four races.

Alonso is second, two points behind, with Ferrari's Brazilian Felipe Massa on 27 and his Finnish teammate Kimi Raikkonen fourth on 22.

Between them, the McLaren and Ferrari drivers have occupied every step of the podium so far this season.

Raikkonen, winner of the Australian season-opener, failed to finish in Spain this month after an electrical problem while Alonso was fifth in Bahrain. Massa was hampered by a gearbox problem in Australia.

Only Hamilton has finished every race in the top three, becoming Formula One's youngest championship leader in the process as well as the first rookie to finish his first four races on the podium.

Alonso played down the rivalry with his teammate, preferring to take the bigger picture in a 17-race championship entering an intense phase with Sunday's showcase race followed by the Canadian Grand Prix in Montreal on June 10 and the US round at Indianapolis a week later.

The Spaniard said he was more concerned about Ferrari's evident pace, with Massa winning the last two races after taking three pole positions in a row.

"To beat the Ferraris these days is so difficult," said Alonso, winner in Monaco with Renault last year. "They are showing a pace that we don't have in a race situation and its very difficult to beat them.

"Once they have a mechanical problem, as Kimi had in Barcelona or Felipe in Australia in the qualifying, for us its a big opportunity to gain points from them."