LONDON, Sept 12 - Renault's world champion Fernando Alonso will miss testing in Jerez this week due to a bruised knee, his Formula One team said on Tuesday.

"I banged my knee on the side of the chassis during practice in Monza, and there is some bruising," the Spaniard said in a team statement.

"I raced with the problem at the weekend, but we took the decision not to test this week to let it recover in the best way possible," he added.

"To be honest, I am really frustrated with the situation because I wanted to be out there testing. We have new tyres, new developments on the car and engine parts to test as well. It will be a very busy and important week in Jerez."

Alonso's championship lead was slashed to two points from 12, with three races to go, at the weekend when Ferrari rival Michael Schumacher won the Italian Grand Prix and he stopped with a blown engine.

That race was also highly controversial, with the 25-year-old Spaniard demoted from fifth on the starting grid to 10th for allegedly impeding Ferrari's Felipe Massa in qualifying.

Renault's champion has spoken out against what he sees as an attempt to favour Schumacher in the German's last season before retirement.

"In Formula One there are commercial and political interests," he told Spain's Radio Marca. "We are talking about the most successful driver in history and a little bit of help has never gone amiss."