The Camp Nou outfit have endured a difficult season and currently sit four points adrift of leaders Atletico Madrid with only three matches to play.
Real Madrid are two points behind Barca in third, but Carlo Ancelotti's men boast a game in hand.
However, Busquets insists his club have not given up hope of retaining their crown.
"We know that things are out of our hands and that it's going to be difficult, but we still have hope," he said. "We have to use every chance we have left.
Atleti have upset the odds this season under the leadership of Diego Simeone and are aiming to win their first league title since 1995-96.
"They are there on their own merit," Busquets continued. "All we can do is keep fighting to win until the last minute of the last game.
"We still have to see what happens in the league, but in terms of results it hasn't been a good season for us."
Last Friday, former Barca coach Tito Vilanova tragically passed away at the age of 45 after a long battle with throat cancer.
Barca subsequently came from two goals down to beat Villarreal 3-2 in their next fixture, but Busquets revealed it had been difficult to prepare for the game at El Madrigal.
"We are people like anyone else and it was hard to play that game," he added. "But we had to put it all behind us and go out and fight for the three points.
"Tito will be on our minds in all the games we have left."
Barcelona host Getafe in La Liga on Saturday.
