Los Colchoneros pipped city rivals Real Madrid to the trophy last campaign, while their hosts eventually finished in eighth spot after a mixed season.
Match preview
Having fallen well short of top spot in terms of points in the previous four seasons, never finishing within 10 points of the top spot, Diego Simeone led Atletico Madrid into the 2020-21 season with the quiet confidence that they could finally secure the title.
Los Colchoneros established themselves at the summit of the top flight at the half-way point of the season, having collected 54 points from their opening 21 games, with their impressive consistency looking set to fire Simeone's men to the title.
However, it would not be that easy, as defeats to Levante, Sevilla and Athletic Bilbao saw the race for the title become tight at the end of the season.
The loss to Athletic saw them briefly drop behind Real Madrid and Barcelona, but they would regain the lead and needed to win their last three games to seal the trophy with their city rivals just two points behind.
Simeone's men did what was needed and dug out three consecutive hard-fought 2-1 wins, finally defeating Real Valladolid to bring the title back to the Estadio Wanda Metropolitano for the first time since 2014.
With Barcelona and Real Madrid both going through tough periods, Los Colchoneros will certainly see this season as a great opportunity to add another La Liga trophy to their cabinet, and will be keen to begin with a victory in a tough away clash.
Celta Vigo will head into the upcoming domestic season with confidence, as they look to battle hard for a top-six finish this time around.
Following a poor start to the season, Eduardo Coudet's side dropped to the foot of the La Liga table after 10 matches, but they quickly turned their form around to climb into the top half.
At the half-way point, the Sky Blues sat eighth, and would continuously bounce around the upper mid-table, before a run of four straight wins, including an eye-catching 2-1 victory over Barcelona, fired them back to eighth place with one game to go, and a 3-2 defeat to sixth-placed Real Betis would not cause any further fall.
Los Celestes should now turn their attention up the table, as they aim to make the brief runs of impressive form a more common fixture this time around, with the objective of achieving a top-seven finish and earning European qualification for next season.
Celta Vigo form (all competitions):
Atletico Madrid form (all competitions):
Team News
Celta Vigo come into Sunday's opening game with a clean bill of health, although Coudet may have to wait for summer signings Javi Galan, Franco Cervi and Jose Fontan to be fully registered before they can feature, given the league's ongoing enforcement of salary caps.
If deemed available, Galan should certainly start on the left-hand side of a back four after an impressive campaign for Huesca last season.
Their line will be led by the threatening duo of Iago Aspas and Santi Mina, after they registered a combined 26 goals and 17 assists in La Liga action last season.
Renato Tapia impressed for Peru at this summer's Copa America, and he should start in front of the back four, shielding the centre-back pairing of Nestor Araujo and Joseph Aidoo.
Diego Simeone will certainly have a big decision to make at the start of the season, as to whether to stick with his tried and trusted 4-4-2, or go revert back to the system of three centre-backs that produced an impressive run of performances and results at the start of last campaign.
He could line up with a back three of Jose Gimenez, Stefan Savic and Mario Hermoso, with wing-back spots up for grabs between the likes of Kieran Trippier, Yannick Carrasco, Thomas Lemar and makeshift full-backs Saul Niguez and Marcos Llorente.
Luis Suarez should lead the line if he is deemed match fit after returning to the squad late from international duty, having fired them to the title with 21 league goals last season, while Portuguese star Joao Felix is ruled out through injury.
Simeone added to his midfield ranks in the summer with the impressive capture of Rodrigo De Paul from Udinese, and he should slot straight into the side on Sunday.
Celta Vigo possible starting lineup:
Blanco; Mallo, Araujo, Aidoo, Galan; Tapia; Nolito, Suarez, Mendez; Aspas, Mina
Atletico Madrid possible starting lineup:
Oblak; Savic, Gimenez, Hermoso; Saul, De Paul, Koke, Carrasco; Llorente, Lemar; Suarez
We say: Celta Vigo 0-2 Atletico Madrid
Despite facing a tough test to start the season, we can only envisage Simeone's side beginning with a victory on Sunday.
Given the situations at Real Madrid and Barcelona, Atletico Madrid have reason to be confident that they can retain the title this year, and a winning start for Los Colchoneros will be crucial to help build a positive run and establish themselves at the top end of the division.