A 1-0 first-leg win for Edgaras Jankauskas's side makes them overwhelming favourites to remain in League C, while Gibraltar are set to drop into the bottom tier.
Match preview
As League D is being shortened to six nations for the next instalment of the Nations League this autumn, due to Russia's expulsion from UEFA competition, only one side will be relegated from the 2022-23 edition.
As the two worst performers from League C, Lithuania and Gibraltar have been condemned to a playout, to decide who will drop into League D for autumn's edition.
A group containing San Marino and Liechtenstein awaits the loser of this tie, while Romania, Cyprus and Kosovo are who the victors will face.
After the first leg, it appears highly likely that Lithuania will be the side that remains in League C, as Armandas Kucys's strike separated the sides in the Algarve.
Despite that being just Lithuania's third away win in 20 games, they do bring much more form into this tie than their opponents.
Six points from eight Euro 2024 qualifiers saw Lithuania finish above Bulgaria, who they beat 2-0 away in Sofia during that section.
Draws against Greece, Montenegro and Hungary also made it a successful 2023 for Lithuania, and they will look to take that into this second leg, and the Nations League starting in September.
Gibraltar had a woeful 2023, and that continued with Thursday's defeat, as their long scoreless run goes on.
Julio Cesar Ribas's side failed to score a single goal in 2023, losing all 10 internationals, conceding 46 goals in the process.
They struggled to lay a glove on Lithuania in the first leg, and were lucky to not lose by more, registering just 0.33 xG, compared to 2.42 for their visitors.
An early red card to goalkeeper Dayle Coleing did not help, but even after the numbers were evened up at 10 each in the second, Gibraltar were unable to capitalise.
Lithuania Nations League form:
W
Lithuania form (all competitions):
L
W
D
L
L
W
Gibraltar Nations League form:
L
Gibraltar form (all competitions):
L
L
L
L
L
L
Team News
Edvinas Girdvainis will miss the chance to win his 50th Lithuanian cap here, after the defender was sent off for picking up two bookings in the first leg on Thursday.
The match-winner Kucys netted yet again, after also doing so in his previous two matches for club side Kauno Zalgiris, and he should come into the starting XI for this one.
On the wings is likely to be Arvydas Novikovas and Fedor Cernych, who have now amassed 184 caps between them, and are the two most experienced players in the squad.
Goalkeeper Coleing is suspended after his red card in the first leg, so Bradley Banda is set to deputise after being the man to come on following the dismissal.
Seventeen-year-old Manchester United midfielder James Scanlon made his international debut off the bench in the first leg, and could be set for more game time here.
Kian Ronan is the only other capped English-based player in the squad, and represents King's Lynn in the National League North.
Lithuania possible starting lineup:
Zubas; Lasickas, Utkus, Kazukolovas, Sirvys; Slivka, Gineitis; Cernych, Kucys, Novikovas; Paulauskas
Gibraltar possible starting lineup:
Banda; Annesley, Hartman, Chipolina, Olivero, Britto; Ronan, Walker, Sergeant, Lopes; De Barr
We say: Lithuania 2-0 Gibraltar
Lithuania are not a side who score many goals, but they created more than enough chances in the first leg to win by a bigger margin.