The Spanish champions recorded a 4-0 win over Mallorca on their return to action at the weekend, while Leganes lost 2-1 at home to Real Valladolid to remain inside the relegation zone.
The result helped Quique Setien's side move five points clear at the top of the table, although second-placed Real Madrid will have the chance to close the gap to two once again when they face Eibar on Sunday.
Barca are in charge of their own destiny at this stage, though, despite the fact that they have already suffered five defeats from their 28 league matches during the 2019-20 campaign.
The Catalan giants will expect to overcome Leganes on Tuesday, but they then have a difficult game away to Sevilla on June 19 before a tricky home clash against Athletic Bilbao on June 23.
There are bound to be twists and turns in the title race over the next few weeks, but Barca's impressive result and indeed performance against Mallorca suggests that they are up for the challenge.
Leganes, meanwhile, will enter Tuesday's contest off the back of a disappointing home defeat to Valladolid on Saturday, which has left them in 19th position in the table.
Javier Aguirre's side are now level on points with basement side Espanyol, although they are only three points behind Celta Vigo in 17th and still have plenty of time to escape the relegation zone.
It is going to be difficult for the visitors to pick up a positive result on Tuesday, but Los Pepineros have a huge game against Mallorca on June 19, which could prove decisive in their battle against the drop.
Leganes finished 13th last season after only just staying in the league in 2016-17 and 2017-18, but there is no question that they are currently locked in a fight to secure their status at this level.
Barcelona La Liga form: WWWLWW
Barcelona form (all competitions): WWDLWW
Leganes La Liga form: LDLDWL
Ousmane Dembele is still on the sidelines for Barca with a long-term hamstring injury, while Alba is suspended due to the yellow card that he picked up in the win over Mallorca.
Luis Suarez was named on the bench at the weekend, but the Uruguay international, who has recovered from a knee injury, could return to the front three alongside Messi and Antoine Griezmann, with Braithwaite dropping out despite getting his name on the scoresheet last time out.
As for Leganes, Argentine attacker Alexander Szymanowski is again expected to miss out with a knee problem, but Aguirre's side have no fresh injury concerns ahead of their trip to Camp Nou.
Barcelona possible starting lineup:
Ter Stegen; Semedo, Pique, Lenglet, Firpo; Vidal, Busquets, De Jong; Griezmann, Suarez, Messi
Leganes possible starting lineup:
Cuellar; Silva, Omeruo, Awaziem, Bustinza; Rodrigues, Mesa, Amadou, Rosales; Carrillo, Rodriguez
We say: Barcelona 3-0 Leganes
It is very difficult to make a case for Leganes on Tuesday taking everything into consideration. Barca were excellent against Mallorca on Saturday and should have far too much for the visitors, who have only picked up one league victory on their travels during the 2019-20 campaign.