Shelvey was outstanding in Tuesday night’s 6-0 win over Queens Park Rangers.
He’s shown some serious faith in me this year by playing me.
The midfielder scored two goals, one of them a stunning 25-yard effort, at Loftus Road.
Shelvey celebrated his goals wildly in front of United’s 3,005 travelling fans. But some supporters questioned the club’s decision to sign him earlier this year.
Shelvey struggled for form in the latter part of last season following his £12million January move from Swansea City.
The England international worked through the summer to prepare himself for the Championship. And the 24-year-old – who crossed paths with Benitez briefly at Liverpool earlier in his career – feels he is now playing some of the best football of his career after putting a difficult start to life at Newcastle behind him.
However, Shelvey admitted ahead of this afternoon’s home game against Wolverhampton Wanderers that no player is guaranteed a start this season.
Asked about Benitez’s influence, Shelvey said: “It’s just nice to have someone show a bit of faith in you by picking you to play.
“We never know the team until less than two hours before kick-off so you’re just still guessing.
“He’s keeping everyone on their toes and making sure everyone prepares correctly for every game.
“It’s just part and parcel of football but he’s shown some serious faith in me this year by playing me.”
Asked if he was playing some of his best football now, Shelvey added: “Yes. Obviously, I feel at the top of my game at the minute.
“I feel I’m playing well and performing well within the team. I’m playing games and that’s what you want.”
Shelvey was involved with England under Roy Hodgson, but he didn’t make the squad for Euro 2016. International recognition, however, is not in Shelvey’s mind right now.
Asked about his chances of an England recall under Sam Allardyce, Shelvey said: “Obviously, it’s going to be harder because you’re playing in the Championship.
“But that’s not my main focus at the minute.
“My main focus is to keep playing well for Newcastle United Football Club.
“There’s a new set-up now within the England squad, so I don’t know how Sam Allardyce is thinking.
“It’s just part and parcel of football.
“If he comes to watch a one of my games, he comes to watch one of my games.
“The only thing you can do is keep performing on the pitch.”
Benitez, however, feels Allardyce should take a close look at Shelvey – and other English players – in the Championship. Asked about Shelvey and England, he said: “If he can keep his consistency, if he can keep working as hard as he was working and playing at the level he has been playing, then why not?
“And not just him. Any player. The Championship is a very good level now. There are a lot of good English players in this league.
“You don’t have too many in the Premier League.
“Every year in every country – it’s the same in Spain – everybody is complaining saying there are too many foreign players coming and we don’t have any space for the English players.
“You have less in the Premier League, but you have more in the Championship.”
Benitez feels Allardyce will be well-informed about Shelvey’s progress. He said: “You have a lot of media, TV and people at the game who can give you reports.
“So if someone scores a goal, like Jonjo did at QPR, and everybody is talking about him, then I’m sure he (Allardyce) will have the information to see if Jonjo can stay at this level or even any of the other players can.”