"I'm happy to play anywhere," he said, with the national manager sitting alongside for Dyer's first media inquisition as an England player. "I like to play in centre midfield - but, in saying that, I like to play right-back now." Which is just as well.
Playing in his preferred position, Dyer has been an outstanding member of England's Under-21 side over the past two seasons, not to mention the Ipswich team that has narrowly missed promotion to the Premiership for three successive years. Despite his vowed intention to remain with his home-town club through thick and thin, Ipswich's latest play-off failure was Dyer's final involvement with the club as a pounds 6m move to Newcastle United proved irresistible.
No sooner had he arrived at St James' Park, however, than Dyer might have been excused for wondering what he had let himself in for. But he insisted yesterday that Ruud Gullit's departure and the arrival of another former Ipswich favourite, Bobby Robson, as manager has had little effect on him and it is certainly true that Dyer was one of the few Newcastle players to emerge with any credit from the 5-1 mauling by Manchester United earlier this week.
"It hasn't been unsettling for me because I'm young and I just want to play football," Dyer said. "But now that we've got a new manager, hopefully he can change it around. For a club of Newcastle's size it's been a disappointing season."
Keegan himself had no qualms about giving the 20-year-old his debut. "Absolutely no doubt in my mind," the England manager said. "I've seen him improve an awful lot from when he started at Ipswich. I believe he's one of these players who you can put in four or five different positions and his training has been superb.
"I saw his game against Tottenham at White Hart Lane where I thought he did two great jobs: he tracked David Ginola back and then he got forward and I thought his first-half performance was as good as you will ever see from a 20-year-old. I think he's a real star of the future because he's got his feet on the floor. I can see him staying in the side if he produces. He has enough confidence without being cocky."
The confidence Keegan refers to was evident enough yesterday. "No disrespect to Luxembourg, but it's a great game to make you debut," he said.
"Being in the England squad I haven't looked out of place and that in itself has given me the confidence. Having said that, if we were playing Brazil in Rio then you would see a different young man in front of you; I'd be on the toilet."
Against Luxembourg, Dyer is likely to be asked to push forward as much as possible on the right-hand side, something which should come naturally to such an attacking player. "When I first broke into the first team at Ipswich they played me at right-back and wing-back," he said. "I liked it at right-back because one of my biggest assets is my energy. I bomb forward quite a lot, overlapping and getting good crosses in. Hopefully I can do the same for England."
Dyer was called up for his country once before under Glenn Hoddle without making the team and, when he heard the news of his elevation, he was understandably beside himself. "The manager told me yesterday morning but the problem was we were going off to training straight away," he said. "It was so hard keeping it inside, I just wanted to run upstairs in the hotel and get on the phone. But I had to wait two hours. As soon as I was back I think I was on the phone for two-and-a-half hours, ringing up every friend. It was just unbelievable. I wish the game was today, that's how excited I am about it. I felt playing at Old Trafford was going to be the biggest highlight of my week but I was wrong."
The contrast between England's two full-backs today could hardly be greater with Stuart Pearce, nearly twice Dyer's age and a very different character, playing on the left. "Stuart is one of those who's psyching himself up before every game," Dyer said, reflecting upon the brief spell when their paths crossed at Newcastle. "I'm very relaxed, just sitting in the corner usually with my headphones on listening to garage-type music."
Whatever happens today and in the future for Dyer, he is determined it will be an occasion to remember. "I think there are 17 members of my family coming up for the game so it will be a big day for me and a big day for them as well," he said.