Euro 2016 marks a historic feat for both sides as Wales are set to make their first appearance at a major tournament since 1958. On the other hand, Slovakia are making their debut as an independent nation at the European Championships.
Wales - Gareth Bale is the star of a Welsh side that performed well in qualifying for the tournament. Chris Coleman's side finished second behind Belgium and were led by Bale, who netted seven times. Wales' final friendly ahead of the tournament ended in defeat as Sweden beat them 3-0.
There are a few injury concerns heading into the opener on Saturday. Joe Ledley continues his comeback from a broken leg, suffered a couple of months ago, and is unlikely to feature. Joe Allen is carrying a knee problem but should be fit in time for Wales' opener, as should Hal Robson-Kanu, who is recovering from an ankle injury.
Projected XI: Hennessey; Gunter, Chester, A. Williams, Davies; Ramsey, Allen, King; Bale, Vokes, J. Williams.
Slovakia - Like their opponents, Slovakia finished their qualifying group in second and were led by their talisman, Marek Hamsik, who scored five times. Ján Kozák's men enjoyed an impressive build up to this summer's spectacle, avoiding defeat in all three friendlies and beating the world champions, Germany, in the process.
A couple of players are battling a few injuries with the opener on the horizon. Tomas Hubocan is still doubtful with a heel injury while Norbert Gyomber will likely recover from his toe problem in time.
Projected XI: Kozacik; Durica, Skrtel, Svento, Pekarik; Hamsik, Kucka, Hrosovsky, Duda; Nemec, Mak.
Wales are playing in their first major competition since the 1958 World Cup. The two sides have met just twice before with both meetings being won by the away team.
Gareth Bale became Wales' youngest ever goalscorer in a 5-1 defeat to Slovakia back in 2006. The two teams met again in 2007 with Wales winning 5-2.
With both countries making their debuts at the Euros this summer, experience is difficult to come and neither squad has a player with over 100 caps for their country.
Players to Watch
Wales - Gareth Bale: The most expensive footballer in the world is the player to watch in this game, and with good reason. Bale directly contributed to 33 goals in 34 games for Real Madrid this season, scoring 20 and assisting on 13. The winger has bags of pace and is a nightmare to defend against. The Welsh superstar will look to kickoff his Euro campaign in style.
Slovakia - Marek Hamsik: There is a star of a different calibre in the Slovakia side, Napoli's Marek Hamsik. The midfielder enjoyed a solid season with his club and impressed during qualifying, but he'll have a busy day against the Welsh midfield. Hamsik should lead the way for Slovakia if they are to get out of their tricky group.