Giancarlo Fisichella has been forced to sit out this week's Jerez test.

Giancarlo Fisichella will not test at the Jerez de la Frontera circuit in Spain on Friday, the Force India F1 team has confirmed.

The Italian had been due to take over from test driver Vitantonio Liuzzi, but due to a 'minor virus', Adrian Sutil will now complete the three-day programme for the Silverstone-based outfit.

Liuzzi meanwhile was in action today [Thursday] for the second day in a row and despite temperatures approaching the high 30 degrees C mark, he got through his full programme, including putting more miles on the team's new seamless shift gearbox, aerodynamic work and brake testing.

In the afternoon, he also tested the new-for-2009 slick Bridgestone Potenza tyres and in total he did 86 tours, his best lap a 1 minute 19.544 seconds, which left him fourth fastest on the unofficial time sheets.

"We continued on with yesterday's programme and once again had a very positive day. We could do over 80 laps with the new gearbox without any reliability issues," explained the ex-RBR and STR man. "We also completed some aero work with the new wheel spinners and in the afternoon went onto the 2009 slick tyres to try the different compounds, weight distribution and the set up.

"I enjoyed it a lot as there is much more grip and the car seemed very well balanced with them. Finally we did some brake testing to finish off what's been a very positive two days of testing."

Force India's chief race and test engineer, Dominic Harlow agreed that it has been another productive day with no mechanical issues halting proceedings.

"This morning we worked through a programme of different set-up options and aero development work and continued to put more mileage on the seamless shift gearbox, which again worked very well," he added.

"In the afternoon we tested the slick tyres, comparing the development hard and soft compounds that will be introduced next season, and also some further work on the brakes. Adrian will take over tomorrow [Friday] to continue the programme as planned."