Barcelona boss Luis Enrique has said that his team "have to keep winning' despite their success in 2015.
The Catalan outfit won the Champions League, Copa del Rey and La Liga title last season and capped that off by lifting the Club World Cup in Japan at the weekend.
Enrique has refused to dwell on the success, however, and is now switching his attention to the trophies on offer in 2016.
"In football, the future is always uncertain. You tend to generalise, depending on what you've already seen, what the future will be like," Enrique told reporters.
"Now we can say that we capped off last season with a fifth trophy. This was a clear goal for us. It's our turn to enjoy a few days with our families and think about the challenges ahead.
"We have to keep winning, which always creates difficulty, but I'm optimistic, seeing how we face our challenges and how we have fun."
Barcelona return to La Liga action against Real Betis on December 30.