The hosts are top of the standings with 13 points from five matches, one point better off than opponents Finland, whom they beat 1-0 in the reverse fixture two months ago.
Continuing with the theme of their entire campaign to date, Wales produced an underwhelming display in Sunday's clash with Republic of Ireland but still got the job done.
David Brooks scored the only goal of the game in what was the sixth meeting between the sides in three years, ensuring that the Dragons are in control of their own destiny.
All four of Wales's Nations League victories have come by the same 1-0 scoreline, although they are usually made to wait until later than the 66th minute to find the breakthrough.
The win over Republic of Ireland makes it one defeat in 13 matches for Wales - a 3-0 friendly loss to England last month - in a run stretching back to June 2019.
In competitive matches, it is seven games without a defeat for Wales, keeping a clean sheet in each of those games in what is their best ever defensive streak.
Finland have had a near-perfect campaign of their own, the only blemish being a late 1-0 loss to the Dragons when the sides met in Helsinki on September 3.
Not only have the Eagle-Owls won all five Nations League games since then - conceding just once - they also beat France 2-0 last week in a shock friendly result.
Indeed, Markku Kanerva's men found life a little tougher away to Bulgaria on Sunday, hanging on to secure a 2-1 victory that keeps them hot on Wales's heels.
Finland must now beat Wales - something they have only achieved four times in 13 previous attempts - if they are to leapfrog their opponents and claim top spot.
Wales Nations League form: LWWDWW
Wales form (all competitions): WLDWDW
Finland Nations League form: LWWWW
Finland form (all competitions): WLWWWW
Given the importance of this home clash with Finland, stand-in Wales boss Page is almost certain to start Bale once again on Wednesday, with minimal changes expected.
That could be a big blow for the visitors, especially with Teemu Pukki scoring only once in five Nations League outings to date.
Wales possible starting lineup:
Ward; Roberts, Mepham, Rodon, Davies; Ampadu, Smith, Brooks; Bale, Moore, James
Finland possible starting lineup:
Hradecky; Alho, Toivio, Arajuuri, Uronen; Lod, Sparv, Kamara, Taylor; Pukki, Forss
We say: Wales 0-0 Finland
Wales have kept five clean sheets from five in League B Group 4, while Finland have shipped only two goals so far.
The visitors enter this game in good form on the back of last week's stunning win over France and narrow victory over Bulgaria, but the Dragons know a point will do and should have enough to grind out a draw.