"The club would like to offer its sincere condolences to the family of the player.
Benitez had recently joined the club from Club America for three seasons.
The player participated for the first time with the team during yesterday's match against Qatar Sports Club in the Sheikh Jassem Cup without complaining of any health problems.
His sudden departure is a big shock for each member of the technical and administrative staff.
He was a player that over the short period he was here was regarded for his high moral character."
More top news
Very windy but largely dry.
Strong winds slowly easing tonight, feeling fresher tomorrow.
West Bromwich Albion are back in the top half of the table but Leicester City stay in the bottom three after a 1-1 draw.