The midfielder joined the action with team-mate Dele Alli in the 63rd minute at the Jose Rico Perez Stadium, home of Hercules CF in Alicante. That meant there were four Spurs players on the pitch with Harry Kane and Kyle Walker both starting.
A first cap was just reward for Eric after a phenomenal start to the season in a new role at Spurs.
He made 36 appearances at right-back and centre-back in his first season for us last term and was switched into the holding role in midfield by Mauricio Pochettino in pre-season.
The 21-year-old has responded in style with performances that have seen him start 16 of 17 matches (missing one through suspension) and now earn his first England cap.
We caught up with Eric after Spain ran out 2-0 winners on Friday night.
It’s one of the moments all English players dream of – their senior England debut – how was it when you stepped out there against Spain?
Eric Dier: “It’s one of the aims you set out to achieve when you start your career so to have achieved it so early is a dream come true and a very proud moment for me and my family.”
Below: Eric in the thick of the action with Kyle Walker and Dele Alli in Alicante
You were on the bench for 70 minutes, what was it like watching that level of opposition – the reigning European champions – and then going on to play against them?
Eric: “Spain are a fantastic team with lots of players that I looked up to growing up so to watch them play and then come on against them wasn’t the easiest way to make a debut, but a good way at the same time. It doesn’t get much tougher than Spain and that is what you want to test yourself against both as a team and as an individual.”
It was great from a Spurs perspective to see you and Dele go on at the same time. Did you say much to each other?
Eric: “It was nice to make my debut coming on at the same time as Dele and hopefully in the future there will be more games alongside each other. To be honest, we didn't really say anything!”
It must all seem a bit surreal – it doesn’t seem a second ago that the pair of you kicked-off pre-season in training friendlies at Hotspur Way in July, now you are playing together in the Premier League and for England against Spain! It’s been an amazing start to the season for you both. Have you sat back and thought ‘wow’?
Eric: “It’s all happened so quickly, I haven't really had a chance to sit back and think about it all yet. I prefer to just put my head down and keep going. I’ll have a lot of time to think about it when I’m retired!”