Sergio Perez had yet another disappointing qualifying performance at Silverstone, as he was left stranded in the gravel with an early Q1 exit. The Red Bull driver will start on the final row for the British GP, slated for this Sunday, July 7.The qualifying session was affected by rain, with drivers initially setting the times on intermediate tires in the Q1 session. Midway through the session, the track transitioned to slicks, with Perez losing the rear of the car on his out-lap. He drifted into the gravel, beaching his RB20 at the Copse corner.Sergio Perez elaborated on the incident that ended his qualifying run. Perez said he was trying to bring his tires into the temperature window while entering Turn 9 and lost the rear of the car, before finding himself in the gravel. He insists the corner was tricky for slick tires, but admitted that he made a mistake."I was trying to warm up the tyres going into Turn 9 when I downshifted and lost the rear end and went off the track. Cold tyres and water off the track and I ended up going into the gravel," he was quoted as saying by Racingnews365.com"Unfortunately, I was the first one probably to go through that corner on a slick tyre, cold tyres, so everything combined, it was the result. Even probably 20 minutes after, it was still a tricky corner. But anyway, I put my hand up because I f**ked up today. Tomorrow is a new day," he addedPerez has been on a poor run of form in recent weeks, with his P19 starting position for the British GP marking his third Q1 exit of the season. With McLaren, Mercedes, and Ferrari closing the gap to Red Bull, the Mexican driver has failed to crack the top five since the Miami Grand Prix.Despite recently securing a two-year extension at Red Bull, Sergio Perez's future with the team reportedly remains uncertain. However, he is confident about keeping his seat and remains focused on turning things around.Christian Horner admits Red Bull can't "afford" Sergio Perez's Q1 exitsAmidst rumors suggesting Sergio Perez could be replaced, Red Bull Racing team principal Christian Horner has acknowledged that the team cannot afford to have a driver starting at the back of the grid as the race for the constructors championship intensifies.Horner said that Perez was disappointed with the qualifying result, and stressed that the Mexican driver needs to put on a good performance on Sunday. Dutch F1 reporter Erik van Haren quoted the Red Bull team principal as saying:"Nobody is more disappointed than Checo. We can't afford to go out in Q1. He needs a 'big race' tomorrow."Sergio Perez will start the race on the final row. Meanwhile, Max Verstappen, Perez's teammate who also had a difficult qualifying session, will start the 52-lap race on the second row.