Benitez said: “We are also looking for young players, but Arsene Wenger has been working on this for 10 years, we have been doing it for just a couple.
“But we need to keep trying our best in the market and work quickly if you have the money.
“And if you have money then you must work at bringing in the best young players.”
He added: “I do not really like to talk now about who we want and who Arsenal have signed, that would be too easy.
“But they have two or three players that we were monitoring and we couldn’t sign because we didn’t have the money.
“But we have to keep going, to do the same thing as Arsene. But if you want top-class players you must spend money, not only at senior level but at youth level too.
“We know the players, we know the names. We knew about some of these players that Arsenal have signed, we had reports on them. But if you cannot pay six million euros for Diaby or Denilson, you cannot buy them.”