Antonio Barreca impressed his Newcastle United team-mates in his first training session.
The left-back joined the club on loan from Monaco on transfer deadline day.
Newcastle also signed Miguel Almiron from Atlanta United in a £21million deal.
Barreca, unlike Almiron, is eligible to play in this afternoon's game against Tottenham Hotspur at Wembley.
And the 23-year-old caught the eye in training yesterday.
Benitez – who kept midfielder Isaac Hayden at the club – says the players are even more "positive" following the arrivals of Barreca and Almiron, who is ineligible to train and play while he waits for a work permit.
"For me, we have two players we didn’t have," said United's manager. "I’m happier than before. Why? We have two players we didn’t have.
"Also, Hayden. I had the conversation with him the other day. He was fine. He knew what he wanted.
"He was a very good professional. He's quite happy to stay here, and has shown his commitment in the games. It’s another positive.
"Then you have the other players – you can see they are more positive. They can see. We were training, Barreca was doing well. I was a player. When you see someone new come and he’s doing things right, you think 'ah right, OK”.
"But that’s good for the team.
"I think everybody is a little bit happier, we won and we have two new faces."