Barca currently sit seven points clear of second-placed Atletico Madrid at the summit, while they will enter the match off the back of an impressive 5-1 win over Lyon in the second leg of their last-16 Champions League tie.
Eleven wins, six draws and 10 defeats - that is how Betis have performed in the league this season. A total of 39 points has left them in eighth position, just one point off sixth-placed Sevilla entering Week 28.
Betis are only six points off fourth-placed Getafe, meanwhile, and there really is a fascinating battle developing for the position behind Barca, Atletico and Real Madrid. Getafe are currently in charge of fourth, but Alaves, Sevilla, Valencia, Betis, Real Sociedad and Eibar are all very much in the mix.
Betis are certainly a team capable of pulling off big results. Indeed, they beat Atletico Madrid at home in February, but have only won twice in all competitions since then. Those two victories, however, have come in their last three league games, winning away at Real Valladolid and beating Celta Vigo last weekend.
The Seville outfit lost 2-1 against Getafe in their last home league match, however, and have not won back-to-back league games since early December, which explains their sitting eighth, rather than further up the table.
Quique Setien's side beat Barca in the reverse game at Camp Nou earlier this season, however, recording a 4-3 victory to shock the hosts. The visitors will be the favourites to triumph in this match, though, particularly when considering that they ran out 5-0 winners in the corresponding fixture last term.
Betis posted sixth in Spain's top flight last season; they have not finished higher than that since the 2004-05 campaign, but will still believe that they can catch Getafe in fourth position.
Setien's team have not struggled to find the back of the net on home soil this season, but have dropped points in eight of their 14 league fixtures in front of their own supporters, which is not exactly terrific form.
Betis will be the fresher of the two teams following Barca's Champions League exertions, however, and it is certainly shaping up to be a very interesting fixture at the Benito Villamarin.
Recent form: WLDWLW
Recent form (all competitions): DLWLLW
The treble is very much on for Barca as Ernesto Valverde's side prepare for a huge couple of months. As mentioned, the Catalan giants hold a seven-point advantage at the top of La Liga and have won each of their last four in Spain's top flight. Not since Betis beat them at Camp Nou have they lost in the league, suggesting that they will not falter from this position.
Valencia will be their opponents in the final of the Copa del Rey at the end of May, meanwhile, and with respect to Los Che, Barca will fancy their chances of collecting another domestic double, which would be seen as another excellent campaign.
The Champions League is the trophy that Barca really want this season, though, having not won the competition since 2015. A 5-1 win over Lyon on Wednesday night saw them progress and they have been drawn with Manchester United in what is a mouth-watering quarter-final two-legged affair.
That is not to say that Barca have been without their problems this season, but Lionel Messi is carrying the charge. The Argentine has 36 goals in 36 appearances in all competitions during the 2018-19 campaign and looks capable of leading his team to the treble this term.
In terms of what is ahead of the Spanish champions, they will return to action after the international break with a home game against rivals Espanyol, before facing Villarreal and Atletico in the league ahead of their trip to United for the first leg of their quarter-final on April 10.
Barca have actually netted in 34 of their last 35 away games in Spain's top flight, while they have put eight goals past Betis in their last two meetings. Indeed, the recent contests between the two teams suggest that Sunday's affair will be extremely entertaining.
The team's stunning form this season means that they have breathing room in the league and it would not be a surprise to see them prioritise the Champions League by resting key players ahead of the two legs with United, who will not have the same luxury as they chase a top-four finish in the Premier League.
Recent form: DDWWWW
Recent form (all competitions): WWWLWW
On-loan attacker Jese Rodriguez scored against Celta last weekend, but Loren Moron is expected to return to the team in a forward position, while William Carvalho and Giovani Lo Celso will also make the XI.
Real Betis possible starting lineup:
Lopez; Mandi, Bartra, Sidnei; Joaquin, Canales, William, Guardado, Tello; Lo Celso, Loren Moron
Barcelona possible starting lineup:
Ter Stegen; Semedo, Pique, Umtiti, Alba; Rakitic, Busquets, Vidal; Coutinho, L Suarez, Messi
Head To Head
As mentioned, Betis recorded a 4-3 win in the reverse match earlier this season, but Barca ran out 5-0 winners when the pair locked horns in the corresponding match last term.
Barca have won nine of the last 11 league meetings between the two teams and have not lost on their travels to Betis since March 2008.
We say: Real Betis 1-3 Barcelona
Betis will fancy their chances of finding the back of the net, but Barca are in stunning form at the moment and should record all three points in Seville to strengthen their grip on first spot in the table.