England currently top the group on four points with Wales and Slovakia following behind on three points and Russia in a precarious position at the bottom of the group on one point.
Reports are suggesting there could be several changes to the England line-up for tonight's game, while Wales are likely to name a similar team to the one that was denied a point in the closing stages against their neighbours.
Slovakia will take confidence from their win over Russia when they face England, while Wales will face a Russia side that have to play on the front foot in order to go for the win to get through to the knock-out stages. That could suit Chris Coleman's men down to the ground.
Here are three players who could make a real difference tonight:
His contribution to England's win over Wales could prove pivotal in the context of the Three Lions' entire campaign having created Jamie Vardy's equaliser, and scored the winner the put them in pole position to finish top of their group.
He is likely to get a start following his 45-minute display in Lens and manager Roy Hodgson will be hoping for a similar impact against Slovakia this evening.
The Wales goal-scoring burden has been almost entirely on Gareth Bale - with Hal Robson-Kanu grabbing the other so far.
Ramsey is the other obvious nailed on starter who can contribute on the scoring front and against a Russia side this evening that has to come out and attack, Wales are going to get chances of securing their passage to the next round of the European Championship. Tonight is a big opportunity for him.
He could be the man who will be a thorn in the side of England, he is undoubtedly Slovakia's most eye-catching player, and found the net in some style in their previous game against Russia.
The Napoli midfielder has been attracting interest from Manchester United and Chelsea, according to TalkSport, but they have also quoted the player's agent saying contract talks have opened with Napoli. A good display from Hamsik would show why the Serie A side would like to tie him down.