"You've played 50 games already?", Shelvey interjects, with genuine surprise. It is, after all, less than 16 months since Hayden arrived at Newcastle with only a handful of senior games under his belt but, should he feature against the Cherries on Saturday, he will reach the half-century mark in black and white.
"It has come around quickly," 22-year-old Hayden admits. "It might have come around a little quicker if I wasn't injured (during February and March) last season but nonetheless, it's a nice milestone to get to and hopefully I can build on that and get to 100, then 150 and so on.
"Especially at my age, if you'd said to me before joining that I would have got to 50 so soon, I probably would have questioned that. You always want to get minutes under your belt and try to improve as much as you can because players are getting better and stronger, so the more minutes you can get, the better it's going to be for you.
"And thankfully, the manager trusts me to do the job that he wants me to do. Obviously I'm going to have bad games and good games but I've tried my best and given 110 per cent every time I've played, whether it's ten minutes, one minute or a whole game, and I think the fans appreciate that."
Hayden has made 39 starts and ten substitute appearances in all competitions, and his tally includes all ten of Newcastle's Premier League games so far this term.
He made two League Cup appearances for first club Arsenal and nine Championship starts (23 appearances in all competitions) during a loan spell with Hull, but believes regular football has helped him to develop as a player.
"Compared to when I first joined, I think I've definitely improved tactically," explains the England under-21 international midfielder. "Certainly, I've improved by learning from the manager here, and I think there's the confidence factor as well. When you're playing games - whether that's coming on or starting - you always have to be ready mentally to do your best.
"I feel like I've done that so far in my Newcastle career and hopefully I can continue that for a long time."
When asked to pick the stand-out game from his 49 appearances, Hayden pauses. "I won't say on a personal level, because that'd be a little bit selfish," he replies.
"But probably the best feeling was the Preston game at home, when we beat them 4-1 to seal promotion. I think that was probably the best game because of what was on the line.
"We'd lost the week before, to Ipswich, so people were talking about nerves kicking in and fans were maybe a little bit anxious about whether we were going to do it or not. Preston aren't a bad side, so for us to do it in that fashion as well...
"We went 1-0 up and then they equalised soon afterwards; after that period of time, it could have gone either way but we managed to get the second goal. Then (Paul) Gallagher nicked my goal when he tried to save it on the line!
"I was a bit disappointed with that but it was better for the team, because with (Preston) going down to ten men and Matty (Ritchie) scoring the penalty to make it 3-1, the game was over.
"And I'd probably say that's the nicest 30 minutes of football I've ever had in my life, from when I was nine to now. It was the nicest 30 minutes I've ever had, the most relief for 30 minutes; we knew they were never going to score, they never had any chances, we could keep the ball, we could do what we wanted. We could play five-yard passes, try and score more goals - and we eventually did."
That was appearance number 36 for Hayden and he'd love to mark his 50th with the same result, even if it's unlikely to be as straightforward against Eddie Howe's Cherries.
"Especially with the way we lost to Burnley on Monday, it'd be good to get a reaction - especially at home, to give the fans something to cheer about," Hayden says.
"Before the international break, it's important to go in with a good result."
