FIFA says players involved in the seven-team Club World Cup next month will give samples before they visit Japanese laboratories to prepare individual steroid profiles.
Players selected for anti-doping controls at the Dec. 8-18 tournament will have their results measured against out-of-competition tests.
Teams include Barcelona, the European champions containing Messi, and Brazilian club Santos, the South American winners featuring Neymar.
FIFA has consulted the International Cycling Union, which pioneered the biological passport in sports. The UCI repeatedly takes riders’ blood samples to measure the effects of doping rather than test for banned drugs.