Barcelona striker Neymar has reportedly been put on a special diet by the club's medical staff to ease signs of anemia just days after he made his debut for the club, according to Spanish newspaper El Pais.
The Brazilian international joined the Catalan giants in June for 57 million euros ($75.7 million, £49.5 million) and made his long-awaited debut last week in a 2-2 friendly draw against Lechia Gdasnk in Poland.
However, according to the paper signs of anemia were detected on his return to training after an extended summer break due to his participation in the Confederations Cup.
"Neymar is being treated by Barcelona's doctors for signs of anemia with an adequate diet and complementary course of vitamins," it said on Saturday without quoting a source for the story.
Barcelona were not immediately available for comment, but the club had previously confirmed that the player had his tonsils removed after leading his country to victory in the Confederations Cup.
Anemia is a treatable condition but is thought to be extremely debilitating for top athletes as a low level of hemoglobin in the blood stream can cause excessive levels of tiredness.
The news is also likely to disrupt the club's plans to work intensively on building on the 21-year-old's strength after club doctor Ricard Pruna expressed concerns at his slight weight of 64.5 kilos (142 lbs, 10.2 stone) when he underwent his medical.
Neymar made his home bow against old club Santos on Friday night as he played 45 minutes in Barca's 8-0 destruction of the Brazilians and has travelled with his teammates to take part in coaching clinics in Palestine and Israel before they embark on a tour of Asia with friendlies in Thailand and Malaysia.