Benitez, who led Newcastle to 10th-place finish on their return to the top flight last term, said he was doing everything to strengthen the squad but must operate on a tight budget.
"Unfortunately it's what we have to do," Benitez told Sky Sports on Tuesday. "We have to wheel and deal, that is the way for us. And then we try to continue doing the right things.
"We are trying to sign a characteristic of players, it's not just names, big names, because they will be too expensive for us, but we are trying to sign players that can do a job for the team.
"As soon as the price goes a little bit higher, I know that we cannot buy them, so we have to be realistic with our budget, and then maybe sell some players and buy some players."
British media reports have linked Stoke City with Newcastle winger Matt Ritchie but Benitez confirmed the club are not looking to sell the player.
"We are in the same position as we were last year. He's our player, we're happy with him and we don't want to sell him," the Spaniard added.
"To do a move, too many things have to happen at the same time. I was talking with him this morning, I don't see any change with the situation."
Newcastle kick off their league campaign at home to Tottenham Hotspur on Aug. 11.
(Reporting by Hardik Vyas in Bengaluru; Editing by Ken Ferris)
