The Spaniard, who was named head coach in the summer, got off to an inauspicious start at the weekend, with a first half where they struggled to threaten against the Croats.
England also lost their opener - 3-2 to Spain at Wembley in an entertaining affair - with both sides now looking to kickstart their Nations League campaigns.
Denia, who has beaten the Three Lions at youth level during his career, is hoping to see growth in his Czech side.
Speaking in his press conference ahead of the encounter, he said: "England are one of the best teams in the world. They have unbelievable individual players, and a great association.
"We are focused on our development, to improve our performance. We analyse England a little, but this is an opportunity to grow. It is a very demanding tournament, but we are focusing on our improvement and on our leaders.
"We don’t have time for training; we only have time to recover, but we give all the details to our players."
He added: "We want tomorrow to do a good performance, we want to do a good behaviour, we need the support, the fans, we need the support of everyone to improve our behaviour."
UEFA Nations League
The UEFA Nations League 2026/27 is contested by the national teams of 54 of UEFA's member associations. They're divided into four leagues based on the rankings of the previous edition, with Leagues A, B, and C featuring sixteen teams each, divided into four groups of four, while League D features six teams divided into two groups of three. It begins in September 2026, with the finals in June 2027.
Follow the UEFA Nations League | Read the latest Nations League news
Seven years ago, the Czechs pulled off a big shock in the same stadium against the same opposition when they saw off England 2-1. Only Harry Kane survives from the England team who were humbled in Prague, whilst Vladimir Coufal is the only home player who played in that game.
Coufal did not train with the squad following the press conference, making his participation in the match questionable.
He was tight-lipped over selection too, with a decision set to be made on their starting XI coming after a scheduled training session at Slavia Prague's stadium later on Monday.
One player who could make his bow during the game is Ladislav Krejci. The Wolves defender, well-known to Premier League viewers, came into the camp with a calf injury and was an unused substitute against Croatia.
He is one who could be back, although his manager was non-committal when asked if one of his star players would feature, stating that they are taking care of him as he recovers from the knock he sustained against Everton in the EFL Cup.
Denia explained: "Before the list, for sure, we communicate with every club. During the break, the players are with the Czech Republic; we take care of the players.
"We need the players 100%, physically and mentally. We have four games in this break; we communicate with the clubs. They have the interests in the players, but we care for them just as much as they do."
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Josh Donaldson is a Global Senior Editor and International Football Specialist for Flashscore. From the UK, now living in Prague, Josh specialises in football and cycling and can be found at an obscure ground watching games or on his bike. You can follow Josh on X and read his articles here.
