Longstaff has been one of the success stories of the summer with the Magpies after making the breakthrough in pre-season training and has done so well a loan move to Portsmouth was delayed in order for Benitez to take a longer look at the player.
Asked about Longstaff, Benitez said: “I think he's done well. He did well in the first game and physically he's fine.
“We don't have 22 or 23 players can replace (in a friendly).
“At Hull, we had to give 60 minutes to some players but you can't play all of them.
“In this case, Sean has a good condition and he as to play 90 minutes and he played really well."
“We want to give young players an opportunity."