The hosts, meanwhile, will be aiming for their first ever win in a competitive match.
Match preview
Indeed, San Marino have only ever won one match since becoming an established footballing nation in 1990, when they defeated Liechtenstein 1-0 in a friendly in 2004.
Estonia are actually one of the few teams San Marino have avoided defeat against in the past, when a 0-0 draw in the Euro 2016 qualifiers helped move them off the bottom of the FIFA World Rankings.
In terms of the Nations League, La Serenissima have finished bottom in both of their previous groups, although they did gain two draws last time around. This time they have found things even tougher, being defeated by Malta (twice) and Estonia without scoring a goal.
As such, they are playing purely to try and build some confidence, having drawn 0-0 with Seychelles in a friendly last week.
Estonia, meanwhile, secured an instant return to League C by beating Malta 2-1 on Friday.
Henri Anier's 86th-minute winner ensured that they will travel to San Marino with top spot already secured, although head coach Thomas Haberli may have been disappointed that it took his side so long to bag the three points considering their opponents played the entire second half with 10 men after Jean Borg's dismissal.
The Blueshirts can travel to San Marino without any pressure, although games against the minnows have very little to profit from for most nations, as Estonia found out when embarrassingly being held by them six years ago.
With ranking points to play for and a 100% record to protect, though, Haberli will want to ensure his players carry as little complacency as possible and avoid a repeat of that outcome.
San Marino Nations League form:
L
L
L
San Marino form (all competitions):
L
L
L
L
L
D
Estonia Nations League form:
W
W
W
Estonia form (all competitions):
L
W
L
W
D
W
Team News
San Marino will be without Dante Rossi due to suspension after the defender received his second booking of the competition against Malta in June.
Michele Cevoli is likely to come in at the heart of the defence.
Estonia, meanwhile, lost Mattias Kait and Marten Kuusk to injury ahead of Friday's win against Malta, and neither will make the trip to San Marino.
Captain Konstantin Vassiljev will hope to earn his 144th cap for his nation.
San Marino possible starting lineup:
Benedettini; D'Addario, Fabbri, Cevelio, Palazzi, Grandoni; Mularoni, Golinucci, Battistini; Ceccaroli, Vitaioli
Estonia possible starting lineup:
Hein; Ojamaa, Purg, Tamm, Mets, Kallaste; Vastsuk, Soomets, Vassiljev; Zenjov, Sappinen
We say: San Marino 0-2 Estonia
San Marino are rarely thrashed at this level, so we expect them to make life difficult for the visitors during certain periods.
However, there is little doubt that Estonia are a step up in class from their forthcoming opponents, so their 100% record should remain in tact.