Cielo didn't participate in the 2015 Pan American Games in Toronto, Ontario, Canada, targeting the World Championships, who would happen after some days.

At the 2015 World Aquatics Championships in Kazan, Brazil finished 4th in the Men's 4 × 100 metre freestyle, in a relay composed by Bruno Fratus, Marcelo Chierighini, Matheus Santana and João de Lucca.
César Cielo didn't swim in the final – despite being a participant in the championship, he was suffering with shoulder pain.
According to the doctor of the Brazilian Aquatic Sports Confederation (CBDA), Gustavo Magliocca, Cielo had an inflammation of the supraspinatus tendon.
The injury is considered common in the athletes, and it was being treated with physiotherapy.
Due to the problem, in the Men's 50 metre butterfly, Cielo struggled though the heats and the semifinals, but slumped to 6th in the final.
On August 5, Cielo left the competition due to the increase of his injury.
Cielo didn't participate in the 2015 Pan American Games in Toronto, Ontario, Canada, targeting the World Championships, who would happen after some days.
At the 2015 World Aquatics Championships in Kazan, Brazil finished 4th in the Men's 4 × 100 metre freestyle, in a relay composed by Bruno Fratus, Marcelo Chierighini, Matheus Santana and João de Lucca. César Cielo didn't swim in the final – despite being a participant in the championship, he was suffering with shoulder pain. According to the doctor of the Brazilian Aquatic Sports Confederation (CBDA), Gustavo Magliocca, Cielo had an inflammation of the supraspinatus tendon. The injury is considered common in the athletes, and it was being treated with physiotherapy. Due to the problem, in the Men's 50 metre butterfly, Cielo struggled though the heats and the semifinals, but slumped to 6th in the final. On August 5, Cielo left the competition due to the increase of his injury.
César Cielo