Spain international Llorente has been the subject of widespread speculation about his future after announcing this summer he would not be signing a new contract with Athletic once his current one runs out at the end of the season.
A host of clubs across Europe, including several Barclays Premier League sides, have been linked with the 27-year-old but Athletic intend to make any interested parties wait until next summer to get their man.
Athletic are hoping Llorente can still have an impact on the field before he leaves as Marcelo Bielsa's side attempt to recover from a poor start to the season.
Urrutia told reporters: "I've a feeling these decisions will not please everyone, but I think they are the most beneficial for Athletic.
"We've taken our decision and at the moment we're sticking to it. He's an important player, he's shown that, and the team is more competitive with him. We hope that he continues to score important goals from now until the end of the season."
Llorente was the joint-leading Spanish goalscorer in La Liga last season with 17 goals but has only played a bit-part role this term following his decision to leave the Basque outfit.
Athletic won just two of their opening nine La Liga matches and were knocked out of the Europa League - a competition they finished runners-up in last season - at the group stage.
However, they have climbed up to 12th in the standings following back-to-back wins over Celta Vigo and Real Mallorca in the last fortnight.