A 21-year-old Spanish youth coach who died after coming down with the coronavirus was found to have had a form of leukemia, a preexisting condition that had previously been undiagnosed.

Francisco Garcia, coach of Atletica Portada Alta’s junior team in Malaga, died Sunday and learned he had leukemia only after he was hospitalized with covid-19 symptoms. Although young people appear to have milder or no symptoms, preexisting conditions, like diabetes or asthma, seriously complicate recovery from coronavirus.

“[W]e want to express our most profound condolences to the family and friends of our coach Francisco Garcia who has unfortunately left us today. What will we do without you now, Francis?” the club said in a statement on Facebook. “You were always there with us at Portada or wherever we needed you, helping. How are we going to continue to conquer kilometers in the league? We don’t know how but for sure, we will do so for you. We will never forget you.”

According to the Spanish newspaper Malaga Hoy, Garcia sought medical attention when he began struggling to breathe and he was found to have pneumonia and the virus.

“We are still in a state of shock,” Pepe Bueno, president of the club, told Malaga Hoy. “... I do not believe it. I do not believe it. It seems impossible to me.”

Malaga’s La Liga 2 team tweeted: “From the club we want to transmit to @AtlPortadaAlta our deepest condolences for the loss of one of its coaches, Francisco García, as well as sending a warm hug to his family and friends. Together we must stop #COVID-19.”

La Liga, Spain’s top league, suspended its season last week with Spain’s rate of coronavirus infections rising. Two days after two players announced that they were among five Valencia soccer team athletes and staffers who had tested positive for coronavirus, the team announced that “around 35 percent” of its staff had positive tests.

“Despite the strict measures adopted by the club after their Champions League game [last month] … these latest results show the exposure inherent to such matches has caused a positive test rate of around 35 percent,” the club said in a statement. It went on to add, “All cases are asymptomatic and those involved are currently isolated at home, receiving medical assessment and carrying out their scheduled training plan.”

It did not break down how many positive tests belonged to players, but Ezequiel Garay and Eliaquim Mangala confirmed on social media that they were in isolation after testing positive. Garay became the first La Liga player to announce a positive test Sunday and the club announced that all are “in good health.” Later, Mangala shared similar news.