Jannik Sinner’s defence of the Wimbledon title began not with the authority expected of a world number one, but with a visible struggle against Serbia’s Miomir Kecmanovic on Centre Court. The Italian, who had won all four previous meetings without dropping a set, lost the opener 6-4 after a late break, recovered to take the second 6-3, then faltered again in a third-set tiebreak. Early in the fourth, television cameras captured what analysts described as a red stain spreading on his left shoe, and Sinner received medical attention on court. He continued, moving with evident caution, and held a 4-2 lead when the match was suspended for the day.

Sinner arrived at the All England Club having not played a competitive match since a second-round exit at Roland Garros, where he collapsed physically against Juan Manuel Cerúndolo. In the intervening month, he underwent medical tests in Milan, wore a glucose monitor during training, and skipped the traditional grass-court warm-up events—a strategy borrowed from Novak Djokovic. Italian media reported that Sinner and his team had adjusted his preparation to avoid a repeat of the Paris episode, but the sight of him limping and losing a fourth consecutive set at a major revived the questions that followed him from France.

The opening day’s programme placed Sinner first on Centre Court, as tradition dictates for the reigning champion. Aryna Sabalenka, the women’s world number one, followed with a straight-sets win over Teodora Kostovic, while Djokovic was scheduled to face China’s Wu Yibing later. The absence of Carlos Alcaraz, still recovering from a wrist injury, removed Sinner’s most immediate rival from the draw, but the early evidence suggested that the Italian’s greatest opponent may be his own physical resilience. British and Argentine outlets noted that six Argentines also began their campaigns on Monday, with Juan Manuel Cerúndolo—the man who eliminated Sinner in Paris—among those in action.

Beyond the court, the tournament’s narrative was shaped by Serena Williams’s imminent return to singles competition for the first time since 2022. The 44-year-old American, who will face Australia’s Maya Joint on Tuesday, used her pre-tournament press conference to criticise anti-doping whereabouts rules as “unprofessional” and “unreasonable,” arguing that the system penalises athletes for missing tests outside their designated hour. The International Tennis Integrity Agency responded by clarifying that such misses do not count as strikes, but Williams’s comments, amplified by US and Indian outlets, reignited a debate that has simmered since high-profile suspensions involving Sinner and Iga Swiatek. Djokovic, speaking to reporters, called Williams’s comeback “truly inspirational” and said he had told her so in person.

Sinner’s interrupted first-round match will resume on Tuesday, with his physical condition the central question. Should he advance, a potential semi-final against Djokovic looms, while the women’s draw awaits Williams’s first Centre Court appearance in four years. For now, the defending champion’s path forward is clouded by the image of a bloodied shoe and a body that, once again, appeared to be sending signals its owner could not ignore.