LONDON - Experienced German Nick Heidfeld is on pole position to substitute for the injured Robert Kubica, said Renault's boss Eric Boullier."Nick is here to be evaluated," the Frenchman told reporters at the second pre-season test of the year at the Jerez circuit in southern Spain."Once we have finished our assessment of him, if we are happy with Nick, then we keep Nick. If we are not, we go to Barcelona and we test some other drivers," the autosport.com website quoted him as saying, in a reference to the the next test."We have to develop this car from scratch, so the obvious choice of driver is an experienced one."Heidfeld, without a drive since he left Sauber last year, has never won a race in 172 starts but the 33-year-old does have eight second places to his name and four thirds in a career that started with Prost Peugeot in 2000.Only one driver in Formula 1 history, Italian Andrea De Cesaris, has started more races without standing on the top of the podium.Heidfeld will test at the weekend along with the team's official reserve Brazilian Bruno Senna. Italian Vitantonio Liuzzi and Spain's Pedro de la Rosa, who also turned up at Jerez, are possible other options.GET WELLF1 teams used their cars to send Kubica, who was moved out of intensive care four days after his rally crash in Italy, a 'get well soon' message as they started testing.All bore the Polish message "Szybkiego powrotu do zdrowia Robert (Get Well Soon Robert)" on the sides of their cars. The website of the Formula One Teams Association (www.teamsassociation.org) also carried the same words.A team spokeswoman said the Pole, who suffered serious arm, leg and hand injuries when his car crashed on a minor rally near Genoa on Sunday, would to have further surgery for several hours on Friday.The 26-year-old underwent a seven hour operation involving two teams of surgeons on Sunday to save his right hand and stabilise his condition.Kubica, one of Formula One's brightest prospects and tipped as a champion of the future, has been ruled out for at least the first three months of the season and possibly all of it given the extent of the injury to his right hand."They have to fix the elbow and the shoulder and the wrist. But he is out of danger now and that is the best news we can have," said Boullier."He is recovering well. It is going fast actually, because he is a sportsman, so it is much faster than it would be with anyone else."He started to feed himself today, and everything is moving. Now is the time for sticking all the bones together and educating the muscles, but we don't know how long that will take," he added."All I know for now is that for the next three months for sure he won't be back. After that, it could be four, five six. He needs at least three months to recover physically, and then we see."