By Anurup Chakraborty

Copyright sportskeeda

Lewis Hamilton will not take part in Pirelli’s crucial tire test at Mugello this week, with reports confirming that Guanyu Zhou will step into the SF-25 mule car instead. The decision comes just as the seven-time world champion was set to drive the 2026-spec tires for the first time.The news lands in the middle of a frustrating campaign for Hamilton. Seventeen races into 2025, the Ferrari driver is still chasing his first Grand Prix podium with the Scuderia. The Mugello outing was meant to provide him with early insight into F1’s sweeping 2026 regulation changes, but the opportunity has slipped away.His absence was explained by Simsgazette on X, who cited F1 journalist Rosario Giuliana as the source:”For understandable reasons, Sir Lewis Hamilton will not be present at tomorrow’s Pirelli tests in Mugello. Zhou will take his place.”The Mugello test is a vital checkpoint for Pirelli, which is finalizing its compound choices for the next regulation cycle. This week’s program follows Haas’ opening runs on Wednesday, where Esteban Ocon and rookie Oliver Bearman put a VF-24-based mule car through its paces. They trialed both hard compounds and intermediate solutions under variable conditions, completing over 70 laps between them.Lewis Hamilton drives the (44) Scuderia Ferrari HP SF-25 at Bahrain. Source: GettyFerrari had been scheduled to run Lewis Hamilton and Charles Leclerc on Thursday after a TPC session for Zhou and Arthur Leclerc in the team’s car. Instead, Hamilton will now sit out, while Zhou takes the lead alongside Leclerc in Ferrari’s adapted SF-25. Roman Grosjean is also set to be involved in the wider Pirelli program this week.The 2026 tires represent a significant shift, with narrower dimensions designed to balance the new hybrid power units and active aerodynamics. The fronts will be reduced by 25 millimeters, while the rears shrink by 30 millimeters. The Mugello test is Pirelli’s final on-track assessment before the compounds reappear next February in Barcelona with the first 2026 cars.For Hamilton, this session carried extra weight. Teammates Leclerc and Zhou have already logged mileage on the new designs earlier in the year. Missing out means the Briton will arrive slightly behind in experience with the narrower rubber, given the new regulations will require immediate adaptation.Lewis Hamilton’s absence, however, comes with a deeply personal reason. His bulldog, Roscoe, has been battling pneumonia for a few years, which has now taken a serious turn. Roscoe has stayed with his vet for most of 2025, treated with a vegan diet, acupuncture, and specialist treatment to help Roscoe with the illness.Lewis Hamilton with Roscoe at the Silverstone fan stage in Northampton. Source: GettyRoscoe recovered briefly and made appearances in the F1 paddock this year, at Silverstone, but Hamilton revealed in a recent social media post that his companion needs the thoughts and prayers of fans.Ferrari boss defends Baku team orders call involving Lewis Hamilton and Charles LeclercCharles Leclerc and Lewis Hamilton of Scuderia Ferrari at the Baku City Circuit. Source: GettyLewis Hamilton’s Mugello disappointment follows a tense weekend at the Azerbaijan Grand Prix, where Ferrari’s team orders became a flashpoint. Both Hamilton and Charles Leclerc endured difficult qualifying sessions. Leclerc crashing in Q1 to start 10th, Hamilton exiting in Q2 to line up 12th.The race saw them locked in a long DRS train behind Liam Lawson as Yuki Tsunoda and Lando Norris fought ahead for sixth place. With 10 laps to go, Hamilton, on fresher mediums, closed in on Leclerc, who was struggling on older hards. Ferrari asked them to switch, hoping Lewis could attack Norris. Leclerc complied, but Hamilton failed to make a move on the McLaren. View this post on Instagram Instagram PostIn the final laps, Ferrari instructed Hamilton to return to the position. But despite braking, he crossed the line just 0.464 seconds ahead of Leclerc, prompting reactions from the Monegasque.Team principal Fred Vasseur defended the decision and said post-race:”I think the situation was clear for us, that Lewis had a tire advantage, and we asked Charles to let him go to try to overtake Norris. On top of that, Charles had the issue with the recovery, and we’re not at the top on the engine. I think that it was the best option for us to do this move. We asked to swap back, and it looks like Lewis had a misjudgement on the position of the start and finish line. If we lost something, it was yesterday (qualifying), not today.”Vasseur was clear that Ferrari’s real deficit stemmed from qualifying, which has been an ongoing weak point for Hamilton. In 2023, he registered three Q2 exits – his highest total in a single season. Already in 2025, he has matched that with four Q2 eliminations and one Q1 exit, with seven races still to run.Between on-track struggles and Roscoe’s deteriorating health, Lewis Hamilton’s 2025 has been a season of setbacks.