The meeting between the reigning European champions and the three-time winners of the competition in Gelsenkirchen is the standout tie of the opening round at the tournament.

Top spot in Group B, and a theoretically easier last-16 draw, is at stake as the two sides aim to build on victories in their opening matches.

Italy came from behind to beat Albania, while Ruiz was outstanding as Spain thumped 2022 World Cup semi-finalists Croatia 3-0.

Paris Saint-Germain playmaker Ruiz, 28, set up the opener for Alvaro Morata and scored himself with a classy finish as he outshone all those around him, including Croatia captain Luka Modric.

That game confirmed the importance to Luis de la Fuente's Spain team of a player who was not taken to the last World Cup by former coach Luis Enrique.

"What can I tell you about Fabian Ruiz? He's an exceptional player, he's at the top level. If he wasn't called Fabian you would be talking a lot more about him," said De la Fuente.

"Based on what we've seen from him on a daily basis he's fantastic and has brilliant technique, we know what he brings to the team.

"We should recognise the quality that he has. He has real imagination."

- Back in from the cold -

De la Fuente's relationship with Ruiz goes back to when he was coach of Spain's Under-21 team -- Ruiz was the star player when they won the Under-21 Euros in 2019.

It was around that time that the former Betis man broke into the full Spain squad, and he featured in Luis Enrique's team at the last Euros, when they went out to Italy in the semi-finals.

Yet he was not a starter, and Luis Enrique did not pick him again, meaning he was out in the cold by the time the 2022 World Cup came around.

But Spain's exit in the last 16 to Morocco led to Luis Enrique departing and De la Fuente taking over, and the new coach quickly recalled Ruiz.

"I've been with him since he was very young and his pathway at club and international level has been incredible," said De la Fuente.

"He's the embodiment of the players that have been working hard in the shadows and maybe the media circus is not around him."

It is true that Rodri, widely considered as the world's best holding midfielder, gets more attention in the Spain team.

But Ruiz is a supremely gifted player in his prime, and a key part of a side that is now more direct than under Luis Enrique, when their game was primarily centred on controlling possession.

- Flourishing at PSG -

Ironically Ruiz has flourished this season under Luis Enrique, now his coach at PSG.

He joined PSG from Napoli in 2022 but has only really settled in France since his compatriot became coach last year.

Ruiz ended the season at PSG by scoring the winner in the French Cup final against Lyon.

He was on target again in Spain's last pre-Euros friendly against Northern Ireland, before once more finding the net against Croatia.

"It's important to start with a win in the tournament, especially against a strong Croatia team," Ruiz said after that game.

Next come Italy, as the nations meet at a fifth consecutive European Championship.

Ruiz comes from the same tomato-producing town near Seville as 2010 World Cup-winner Jesus Navas and Barcelona starlet Gavi.

Having emerged at Betis, he moved to Italy with Napoli in 2018 and spent four seasons in Serie A.

There he played under Carlo Ancelotti and Gennaro Gattuso as well as Luciano Spalletti, who will be on the Italy bench on Thursday.

Coming into the Euros, Spain were widely seen as sitting just behind the leading favourites to win the competition.

This is therefore a big test of their credentials.

"We have always said our success comes down to being a team. I don't know if we're favourites or not but we'll try to fight to the end to get to the final," Ruiz said.