Cristiano Ronaldo will undergo further tests in Turin on Thursday as he battles to be fit for Juventus’s Champions League double header against Ajax after picking up a thigh injury on international duty for Portugal. The 34-year-old pulled up injured after half an hour into European champions Portugal’s 1-1 Euro 2020 qualifier draw against Serbia. Juventus said initial tests in Portugal had shown “a minor injury” to Ronaldo’s right thigh, with their Champions League quarter-final first leg tie against Ajax on April 10. Ronaldo flew to Barcelona for personal business on Wednesday, and not for a consultation, with the Portuguese star later posting a photo of himself on social media. Italian media reported the five-time Ballon d’Or had returned by private jet to Turin late on Wednesday with tests scheduled with Juventus medical staff on Thursday morning. But Ronaldo will likely miss the champions next three Serie A games, against Empoli on Saturday, Cagliari on April 2, and AC Milan four days later. “I’m not worried. I know my body. I believe that in no more than two weeks I’ll be fine,” Ronaldo told reporters after the game against Serbia. Juventus’s contingent of international players return to training on Thursday as the champions push towards an eighth consecutive league title. Juventus lead Napoli by 15 points despite losing their last game before the international break 2-0 to Genoa, with Ronaldo rested for the first time this season.