Joselu has been put on standby to face Arsenal.
Newcastle United take on Unai Emery's side at St James's Park on Saturday looking for their first Premier League win of the season.
Loan signing Salomon Rondon has been leading the line since proving his fitness, but the striker – and defender DeAndre Yedlin – will get back late from their internationals in the USA.
Rondon scored two goals for Venezuela against Panama in Miami on Tuesday night, while Yedlin came off the bench for the USA against Mexico in Nashville.
And Joselu – who scored in the club's two previous home games – could be recalled to the starting XI if manager believes Rondon is fatigued.
“This period is quite difficult,” said Benitez. “DeAndre and Rondon will come late. It will be difficult for us, because sometimes they come to us and they say ‘I’m fine’. But they can be tired. Rondon plays in Miami.
“It’s important for us to keep the communication with their medical staff and make the right decision about who plays. Some players are training now and are feeling confident. The others? Who knows?
“In the end, it’s a difficult decision."
Joselu's goals came against Tottenham Hotspur and Chelsea.
Meanwhile, Benitez will also make late decisions on midfielder Jonjo Shelvey (thigh) and winger Matt Ritchie (knee).
“We have had Jonjo training, and Ritchie's still with the physio, but they're pushing," said Benitez.
"These two players are the kind of players that you have to stop them, because they want to play and they're working really, really hard to be there.
"So, we will see. Still, we have some time, but at least Jonjo was training. If we don’t have any problems, he can be there. It’s too soon to say ‘yes’, but I am quite optimistic.”