Sergio Perez heads to his home race in Mexico fighting for his future. Liam Lawson has presented a renewed challenge at RB and forced him to raise his level. Perez saw off the threat of Daniel Ricciardo, who had a chance of replacing him during the summer break. The 34-year-old only signed a new deal in June, but Red Bull can break it. It was a one-plus-one arrangement, with the 2025 season supposedly guaranteed and 2026 optional. But Perez is in breach of contract after falling more than 100 points behind teammate Max Verstappen before Spa. Lawson made an immediate impression at the US Grand …