The 20-year-old Dane has had praise ringing in his ears since an impressive show against Manchester City in the FA Cup, and Wagner is delighted he’s pushing Aaron Mooy, Jonathan Hogg and Dean Whitehead for starts.
As Newcastle United come to the John Smith’s Stadium in front of a sell-out home crowd, Wagner said: “I’m very happy Phil is consistently back on track because he has been at a very high level this last eight to 10 weeks.
“Unfortunately he took time out for three or four months at the beginning of the season, which was very frustrating.
“It’s shown that he now understands how important it is to work hard in every training session and every game.
“In professional football there are no presents because you are a talent.
“What you have shown in the past you have to confirm every single day and he is doing that at the minute.”
Wagner added: “I’m very happy with him because he is showing he is strong and takes the physical part of the game both when he has the ball and when the opposition have the ball.
“He is taking good steps in the right direction, but he is still far away from where I want him to be.
“It is up to us to help him to make that step, because he is a big, big talent.”
Wagner says it was frustrating when Billing wasn’t delivering earlier in the campaign.
“I spoke a lot to him and gave him advice, but he was not able to transfer it on the pitch,” said the boss.
“We can only try and help him, of course. He has taken a little bit longer, but now he consistently performs and this makes me happy.
“I think, too, he is now better and more confident because he has shown how strong he is and that he can help this team get points on the board.
“Now it’s up to him to keep the shirt for as long as he can, but this is what we like to have - competition in every position.”