Lionel Messi started on the bench at Mendizorrotza on Tuesday in a move that made clear just how comfortable Barca are in this title race, its conclusion surely now only a matter of when rather than if.
Should Atletico avoid defeat to Valencia at the Wanda Metropolitano, the Catalans will still be crowned champions on Saturday at the Camp Nou with a victory over Levante.
They could even have it wrapped up before kick-off on Saturday if Atletico fail to take at least four points from Valencia and Real Valladolid, the latter whom they face a few hours earlier on Saturday.
"It's an incredibly valuable win," coach Ernesto Valverde said. "In the end however much as people say the league is won, it has to be achieved on the field.
"We are at the gates now, needing three points more with four games ahead. It is an immense joy to be in this position after so many months of work."
Real Madrid, who play their game in hand against Getafe on Thursday, sit 16 points adrift in third. Alaves stay eighth, their hopes of a Europa League spot fading fast.
Messi came on as a substitute in the 61st minute shortly after his team had scored twice, Carles Alena guiding one into the corner before Luis Suarez, in Messi's absence, took and dispatched a penalty.
Valverde leaving out his captain and star player, presumably with an eye on next week's Champions League semi-final against Liverpool, was a luxury Barcelona have earned and can afford.
Liverpool, still jostling with Manchester City in the Premier League, are unlikely to feel the same sort of confidence when they face Huddersfield on Friday.
"The idea at half-time was to play Leo because the result was not clear," Valverde said.
"But regarding the Golden Boot and that sort of thing, we are only focused on what we have to do to win.
"Leo has a lot of individual challenges ahead but today it was time to rest."
Other players were preserved too. Jordi Alba, Clement Lenglet and Arthur Melo all began on the bench, allowing Samuel Umtiti more minutes as he recovers from a knee injury, while the struggling Philippe Coutinho started in a front three with Ousmane Dembele and Suarez.
Alena, the 21-year-old Spaniard, scored his second La Liga goal and showed again why many believe he could be a key figure for Barcelona in the years to come.
- Consistent Suarez -
Suarez's goal, meanwhile, was his 21st in the league and marks the fourth consecutive season in which he has passed the 20 mark for Barca.
He might have scored earlier but shot straight at Fernando Pacheco when sent clear in the opening stages, while Coutinho followed up but his rebound was blocked.
Sergi Roberto fired over from inside the area but it was his run down the right that created Alena's opener in the 54th minute.
After a neat exchange with Arturo Vidal, Sergi played inside, through the legs of Suarez and to the feet of Alena. He controlled and placed the ball coolly into the corner.
Six minutes later, and one before the introduction of Messi, Suarez doubled the lead from the spot. Umtiti bundled in on the line and as VAR checked him for offside, Alaves' Tomas Pina was shown to have handballed moments before. Suarez made no mistake.
Messi hit the woodwork, his shot well saved by Pacheco, and Coutinho drove wide late on. Two was enough for the win and, possibly, the title.