"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
Rain slowly clearing to sunshine and showers on Sunday.
Outbreaks of rain will move southwards turning clearer and colder.
Heavy showers with a chance of thunder but clearing this evening with clear spells overnight.