The Catalans host relegation-threatened Recreativo Huelva on Saturday and a fifth straight win would increase the pressure on second-placed Real Madrid, who play Real Valladolid at the Bernabeu on Sunday.
"We cannot afford to rest on our laurels and we need to keep working and stay focused," Guardiola said at a news conference after his side all but secured their place in the Champions League last four ahead of Tuesday's second leg in Munich.
"We have another league match on Saturday and we have to focus on that. There'll be time for celebration later."
Barca are still in with a chance of winning three competitions this season - the Champions League, Primera Liga and King's Cup - while Real's only possibility of silverware is what would be a third consecutive domestic title.
However, the club has been distracted by institutional uncertainty surrounding presidential elections due at the end of the season and a reported falling out of influential midfielder Guti and coach Juande Ramos.
Guti gave a surprise news conference on Wednesday in which he described his relations with the former Tottenham Hotspur boss as "cordial".
"But he is counting on other players right now," he added. "My behaviour has been exemplary, like all the players. The coach is the one who selects the team."
COMFORTABLE ADVANTAGE
Third-placed Sevilla, who host struggling Getafe on Sunday, are six points adrift of Real and have a comfortable nine-point advantage over Villarreal in fourth, who play Malaga at home on Saturday.
Improving Valencia, in fifth, appear to have put their financial problems behind them with two straight wins and play at Sporting Gijon on Sunday.
Valencia President Vicente Soriano this week denied a report that striker David Villa and midfielder David Silva had been offered to Real Madrid to raise cash and Villa noted on Wednesday there were six years remaining on his contract.
"If there is to be any movement regarding myself or any other player it won't happen now but in June and having other things on our minds is damaging to the club and to me," he said.
Jose Maria Nogues, who replaced Paco Chaparro as Real Betis coach on Monday after the Seville-based side slipped to 16th, one point above the relegation places, makes his debut at Racing Santander on Sunday.
