A total of nine points from four games has left Markku Kanerva's side in second position in League A Group 4, while Bulgaria are currently bottom of the section, having picked up just a single point from four matches.
Bulgaria will enter Sunday's clash off the back of a victory, having beaten Gibraltar 3-0 in a friendly on Wednesday, but it has been a tough Nations League campaign thus far for the Lions.
Georgi Dermendzhiev's side, as mentioned, are currently bottom of League A Group 4 with just a single point to show from their four matches in the section.
Bulgaria opened their campaign with a 1-1 draw at home to the Republic of Ireland but have since lost home and away to Wales, in addition to suffering a 2-0 loss away to Finland last month.
Lavovete will not be present at next summer's European Championships, meaning that it is now 16 years since they last qualified for a major tournament, and they are facing a major battle with the Republic of Ireland to avoid finishing bottom of this particular section.
Finland, on the other hand, will enter Sunday's clash full of confidence, having recorded an impressive 2-0 victory away to world champions France in a friendly on Wednesday night.
Kanerva's side have now won four of their last five matches in all competitions, including three straight Nations League victories over the Republic of Ireland - home and away - and Bulgaria.
As mentioned, a total of nine points from four matches has left them second in the group behind Wales, and they will want to be in a strong position ahead of their huge trip to Cardiff on November 18.
The Eagle-Owls won four of their six games in the 2018-19 Nations League to earn promotion, while they will be at next summer's European Championships, having finished second behind France in Group J.
Bulgaria Nations League form: DDDLLL
Bulgaria form (all competitions): DLLLLW
Finland Nations League form: LLLWWW
Finland form (all competitions): LWLWWW
The fact that the leading scorer in the current Bulgaria squad - Bozhidar Kraev - only has three international goals to his name is an indication of the team's issues in the final third of the field.
The side will have a different look to the one that started against Wales in their last Nations League fixture, although Georgi Yomov and Kraev should both keep their spots in the XI.
Bulgaria possible starting lineup:
Lukov; Cicinho, Zanev, Dimitrov, Popov; Malinov, Ivanov; Yankov, Tsvetkov, Yomov; Kraev
Finland possible starting lineup:
Hradecky; Granlund, Toivio, Arajuuri, Uronen; Soiri, Kamara, Sparv, Taylor; Pukki, Pohjanpalo
We say: Bulgaria 0-1 Finland
Finland's recent form has been very impressive, but the same cannot be said for Bulgaria, who have lost their last four competitive matches. We are not expecting a particularly open game on Sunday but believe that Finland will have enough to pick up a very important three points.