Benitez has no problems with how Spanish boss Vicente Del Bosque is preparing his players but will urge him to use his star striker a little more sparingly.
He added: "You can't blame the manager or the fitness coach, because Fernando said he was ready. In this case, it is just bad luck.
"But he has had three hamstring injuries with the Spanish national team and it's something we need to analyse, as he has had only one in a year-and-a-half with us.
"For me, the problem is all about playing too many games. If you have two matches, and one is against a country at a much lower level, maybe it would be better giving him a little break."