Samir Nasri will have to explain the intravenous drip treatment he is said to have received at a Los Angeles clinic amid concerns he may have violated anti-doping rules.
The Spanish Agency for Health Protection in Sport (AEPSAD), which handles doping issues in sport, said on Wednesday it was launching an investigation.
The French playmaker is currently on loan from Manchester City to Spanish side Sevilla.
AEPSAD stated on its official Twitter feed: "AEPSAD has initiated the appropriate steps to clarify what treatment was received by the player Samir Nasri."
According to the Drip Doctors clinic, Nasri received its 'Immunity IV Drip'. The clinic states that the treatment involves one litre of hydration, and is designed to "combat superbugs and common viruses".
However World Anti-Doping Agency rules state that there is a 50 millilitre limit for active athletes.
WADA's prohibited list includes: "Intravenous infusions and/or injections of more than 50ml per 6 hour period except for those legitimately received in the course of hospital admissions, surgical procedures or clinical investigations."
Source: PA
