The Catalan club are eight points ahead of second-placed Real Madrid going into the weekend although, with Jose Mourinho's men at Espanyol tonight, the silverware could already be in their hands by the time they kick off on Sunday.
Should Madrid win, though - and their form dictates they may well do - Barca will head to the Vicente Calderon knowing a victory will be enough.
But Atletico have had an excellent season, are headed for the Champions League and pose the sternest of tests.
It will not be Barca's only chance to win the title, but for the avoidance of doubt they want to get things wrapped up as quickly as possible.
"Our game is the biggest for us - whatever Real Madrid do," Barca midfielder Thiago told a press conference ahead of the game.
"The Calderon is never an easy place to go to and win. Atletico Madrid are in next year's Champions League and they are through to the Cup final.
"There's still plenty of time for them to focus on that final and I am sure they will give us a very tough game."
Defeat for Barcelona would not be disastrous but it would end another difficult week on a high, with Vilanova again having been away for treatment on his throat cancer.
While victory for Barca would see them crowned champions, Atletico have celebrations of their own to carry out.
Diego Simeone's men have not been able to continue their scorching early- to mid-season form, but have remained consistent enough to get a top-three spot - something which means Radamel Falcao may well stay with the club.
Simeone is not wanting to get too carried away knowing how tough an opponent Barcelona are, but is still encouraging his fans to enjoy the moment.
"We cannot get away from the next game because we've never approached things differently, we need to look at Barcelona," said Simeone, who is also planning for a Copa del Rey final against Real Madrid.
"We know it will be a difficult game on Sunday, but the fans can get together and celebrate making it to the champions league."