Aston Martin's Sebastian Vettel remains doubtful for this weekend's Saudi Arabian Grand Prix as he has yet to return a negative test for Covid-19, the team said on Thursday. The four-times world champion <a href="https://www.thenationalnews.com/sport/f1/2022/03/17/sebastian-vettel-out-of-formula-one-season-opener-in-bahrain-with-coronavirus/" target="_blank">missed the season opener in Bahrain last weekend</a> after testing positive, with reserve driver Nico Hulkenberg replacing him. Aston Martin revealed Hulkenberg will remain on standby for the race in Jeddah. A statement from the British team read: "Sebastian Vettel has not yet returned the required negative Covid test to fly to the Saudi Arabian Grand Prix. "Nico Hulkenberg will be in Jeddah to deputise for Seb if necessary. "We will delay our final decision until Friday to provide Seb every opportunity to race." Although mandatory testing has been scrapped by Formula One, teams are continuing with the process. F1 has made it compulsory for all team personnel to be vaccinated this year. But drivers can still be banned from the paddock if they return a positive test in a country where isolation is not required. It is understood this is unlikely to change anytime soon. In Vettel's absence, Aston Martin endured a poor start<a href="https://www.thenationalnews.com/sport/f1/2022/03/20/ferraris-charles-leclerc-wins-thrilling-season-opening-bahrain-grand-prix/" target="_blank"> to the new campaign</a>. Lance Stroll finished 12th with Hulkenberg 17th and last.