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.
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."
"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.
