The Spanish midfielder has reminded fans that his side are still in contention in two competitions and declared that Guardiola's tactics for the Clasico were correct
The Catalan giants are all but out of the race for the Liga title after Saturday's 2-1 defeat to Real Madrid at Camp Nou has left the club seven points adrift of Los Blancos in second place, with only four games remaining.
The defeat sees Barca switch their focus to the Champions League and the Copa del Rey, and Xavi believes that the season can still be deemed a success.
"This is not a delicate moment, but one filled with hope," Xavi told reporters at a press conference. "We have in our hands the possibility of having a great season.
"We may have lost the Liga title, but we have won three titles this season. We also still have the Copa del Rey final and there is the possibility that we can reach the Champions League final
"We are competitive, but this team also knows how to lose. That is the way we are.
"We did not have a bad match against Madrid, but we were not excellent either. We could not take advantage of the chances we created."
The Spain international then came out in defence of coach Pep Guardiola, insisting that it was not the coach's tactics that made Barca lose the Clasico.
"Our plan was to go out on attack, so we played with three defenders," he explained. "We had done it at the Santiago Bernabeu before and it worked, but yesterday it did not.
"It was the correct strategy."
Barca will host Chelsea on Tuesday in the second leg of their Champions League semi-final tie, with the Camp Nou outfit looking to overturn a one-goal deficit.