There are three changes to the Cymru starting line-up from the win on Sunday with Neco Williams and David Brooks dropping down to the bench while Ben Davies is suspended.
Connor Roberts comes into the side along with James Lawrence and Harry Wilson for the decisive match that will determine which of the two teams wins the group and with it earns promotion to League A.
Follow @Cymru for live updates throughout the evening.
You may not be aware of it, but Noah Frick scored for Liechtenstein against Gibraltar in their 1-1 draw last night and it was quite a key goal for Cymru.
With Gibraltar conceding for the first time in this UEFA Nations League campaign, Cymru are now the only country out of all of the 55 nations competing in the competition not to concede a single goal.
The campaign comes to a head in Cardiff this evening as Cymru take on Finland in a match that will decide which team not only achieves promotion to League A, but also puts themselves in a strong position to claim a 2022 FIFA World Cup play-off place if required.
Here's a reminder of the current position in League B4 ahead of this decisive fixture.
Wednesday's fixtures!— UEFA Nations League (@EURO2020) November 18, 2020
Who are you backing? #NationsLeague
Rob Page also spoke to the media earlier this afternoon ahead of the decisive UEFA Nations League fixture against Finland in Cardiff on Wednesday (7.45pm).
"It's a big game for many reasons," explained Page. "But for us to be able to go into the World Cup qualifiers and then, irrespective of where you finish in your group, the worst case scenario is you might still get a play-off place.
"It means that there's everything to play for, and we want to finish in style and we want to top the group. The icing on the cake would be to get promotion out of the league as well."
Page also commented on the fitness of his squad after two Republic of Ireland players tested positive for coronavirus following Sunday's match. "Of course it's been a concern for us," he added. "We've tested the players and all have come back negative thankfully. We've had a medical team that have watched the game back and there are no concerns at all.
"Over the three camps we've had since September, the medical team have worked tirelessly to make sure we've got the best care and protocols put in place. It's been heightened by the time of year, the virus thrives on the conditions a little bit more."
It's been a near-perfect Nations League campaign for Wales...— BBC Sport Wales (@BBCSportWales) November 17, 2020
Can they secure promotion to the top tier against Finland tomorrow? pic.twitter.com/XaKbQeTJQh
Gareth Bale spoke to the media from the team base this afternoon and explained how he is quickly returning to full fitness and that he is enjoying his football again.
"I'm just getting my fitness back and being back playing is what makes every footballer happy," said Bale. "I feel like I’m in a good place at the moment, there's still more to come, more to improve, and I'm looking forward to it.
"It does take a bit of getting used to, the body getting back into rhythm of playing every few days, you get a little bit more stiff than usual, but the more games I’m playing the better the body is adapting. It's going to take a little bit of time still but I’m on right path and I'm enjoying playing again.
"It's just about building up, it takes a bit of time, especially when you’re a bit older, but I'm just excited to get back to full fitness. Hopefully it won't be too long, and then leading into Euros in the summer, that’s where I want to be peaking."
Happy 20th birthday to Wales international Dylan Levitt! pic.twitter.com/GPNfy3q3Se— WalesOnline Sport (@WelshSportLive) November 17, 2020
David Brooks scored the only goal of the game on Sunday against the Republic of Ireland and the Cymru star spoke to the media after the match about his return from injury.
"The first game that I played 90 minutes in for 19 months was the game just before this one for Bournemouth," he explained. "I'm just delighted to get 90 minutes last week and 82 minutes here and it's great that I've started to get back on the scoresheet, so I'm just looking forward and trying to stay fit."
A victory against Finland on Wednesday will guarantee Wales' place in the top tier of the Nations League.— BBC Wales (@BBCWales) November 16, 2020
KO: Wednesday, 7:45pm
Live: @BBCRadioWales / @BBCRadioCymru
Highlights: 11.10pm - BBC One Wales pic.twitter.com/Sa2Db0G1Gy
Rob Page and his Cymru squad were back on the training ground earlier today ahead of the crucial UEFA Nations League fixture against Finland in Cardiff tomorrow night (7.45pm).
Jonny Williams missed the win over the Republic of Ireland on Sunday as a precaution and is expected to return to squad having resumed training, while Harry Wilson returns from suspension. Ben Davies will miss the match following his second yellow card of the campaign in Sunday's win.
Here are a few photos from today's training session.
Jesús Gil Manzano will take charge of the UEFA Nations League match between Cymru and Finland on Wednesday night.
The 36-year old official from Spain was promoted to the La Liga list in 2012 and has been a FIFA referee since 2014. In addition to regular appointments in the group stages of the UEFA Champions League and Europa League, Manzano also took charge of four EURO 2020 qualifiers.
More observant Cymru fans may remember that he refereed the FIFA World Cup qualifier between Georgia and Cymru in Tbilisi in October 2017 when Tom Lawrence scored the only goal of the game for Chris Coleman's side.
Manzano will be assisted by Diego Barbero and Ángel Nevado while Juan Martínez Munuera is the fourth official. All of the officials are from Spain.
It's incredible to think that it was one year ago this week that Cymru qualified for UEFA EURO 2020 with a 2-0 win over Hungary at the Cardiff City Stadium.
Midfielder Aaron Ramsey scored both goals in-front of a packed Cardiff City Stadium, but there will be a very different atmosphere in the capital this week for the decisive UEFA Nations League match against Finland as games continue to be played behind closed doors.
A win or a draw on Wednesday will be enough for Cymru to win the group and gain promotion to League A ahead of the next edition of a competition that has proved to be a popular addition to the international calendar.
Click the video below to watch the highlights from that famous win in Cardiff last November.
Defender Ben Davies will miss the decisive UEFA Nations League match against Finland on Wednesday evening after receiving his second yellow card of the campaign during Sunday's win over the Republic of Ireland.
Davies (below) was also booked in the victory over Bulgaria last month. Meanwhile, Cymru welcome back Harry Wilson as the Liverpool winger served has now served his one match suspension.
Finland will be without the services of captain Tim Sparv after the midfielder collected his second booking of the competition in his sides victory over Bulgaria at the weekend.
Matchday 6 predictions?— UEFA Nations League (@EURO2020) November 16, 2020
Promotion, relegation, finals or staying where they are? See what can still happen in the #NationsLeague
Kieffer Moore was the difference between Cymru and Finland when the two teams met at the start of the current UEFA Nations League campaign in Helsinki in September.
Cymru had started brightly with the striker having an early effort ruled out in the opening exchanges after he was adjudged to have committed a foul in the build-up to the goal. It became scrappy in the 2nd half, but the patience of the Cymru side was rewarded when Moore scored the decisive goal on 80 minutes.
"I'm loving my football," said Moore after the match. "Those three points are going to be vital for us. We've been working on breaking fast, and DJ has done the hard work. I thought we played well in most parts of the game."
Former Cymru defender James Collins was covering the match for Sky Sports, and provided his assessment of the striker. "The beauty about Kieffer and the way Wales play is that it gives them the option of playing both ways. You can have Dan James and Gareth Bale on the wings who are tricky and quick, but if Wales are in trouble they can play the ball up to Kieffer and he holds it up so well."
David Brooks was the Cymru hero on Sunday with the only goal of the game against the Republic of Ireland in Cardiff.
The UEFA Nations League victory means that Cymru head into the decisive game against Finland on Wednesday with a one point advantage. Still undefeated, avoiding defeat on the final matchday will guarantee to promotion to League A ahead of the next edition of the tournament.
In addition to remaining undefeated, Cymru are also yet to concede a single goal in the campaign, despite losing goalkeeper Wayne Hennessey through injury. Danny Ward deputised on Sunday and maintained an incredible clean sheet record in competitive games that stretches back to October 2019 when the side were held to a 1-1 draw against Croatia.
Cymru extended their unbeaten run in competitive fixtures to nine matches on Sunday evening with a 1-0 victory over Republic of Ireland, thanks to a solitary goal from David Brooks.
Brook’s goal leaves Cymru a point clear at the top of Group 4 in League B heading into the final round of fixtures, as Cymru host second placed Finland in a winner takes all clash at the Cardiff City Stadium.
Keep checking the Live Match Hub for all the latest information ahead of the game on Wednesday, 18 November.