Rafa Benitez believes that Joselu can make a bigger contribution in front of goal for Newcastle United.
The striker joined the club from Stoke City in a cut-price £5million deal last summer.
Joselu came off the bench to score his fourth Premier League goal of the season in Saturday's 1-1 draw against Swansea City at St James's Park.
The 27-year-old turned and shot past Łukasz Fabianski after Ayoze Perez delivered a low cross into the box.
"I'm happy when any player scores, but especially with the strikers, because then they have more confidence," said Benitez.
"If a player comes off the bench and has an impact, and then continues pushing and working as hard as he was working, that's a very good message for the rest of the team.
"I think it's quite positive to see players pushing and working so hard when they come from the bench.
“In this new world that football is in now, where everything is so expensive, we knew that he could score goals and make a contribution. He is doing that.
"Can he score more goals? Yes. But maybe we would have to pay £25million or something like that. He's doing a great job for the team, and is working really hard. He's scoring goals, and I'm quite happy with him."
Joselu has been in and out of the team in recent weeks.
Asked about the Spaniard's attitude, Benitez said: “It's been really good. It's not just if you score goals – everybody's expecting that a striker has to score goals – but in a team like us, that might not create as many chances as you want.
"Then they have to work hard. All of them are doing that. At the same time, he's scored some goals, so that's positive. His attitude and behaviour has been positive the whole season.”