French rugby player Francois Carrillo has collapsed during the warm-up of a Top 14 match with the Bayonne back-rower suffering what appeared to be a heart problem.

The 24-year-old collapsed after taking the ball at a line out a few minutes before the end of the warm-up session prior to Bayonne's clash with Mont-de-Marsan, an AFP journalist witnessed.

A heart specialist team gave Carrillo cardiac massage before the player was taken to hospital.

"The first examinations are reassuring, according to the doctors at the hospital," said a club statement released later on Saturday.

"Carillo is conscious and stable. The nature of the problem has not yet been clearly determined."