Barcelona's Dani Alves has issued an ominous warning ahead of tomorrow's Copa del Rey meeting with Athletic Bilbao, insisting the rampant Catalans still have room for improvement. Barça host Athletic at Camp Nou in the first leg of their last-16 tie on the back of a 22-match unbeaten run in all competitions, 19 of which have ended in victory.

Moreover, in winning their last ten matches, Pep Guardiola's side have scored 42 goals and conceded just four - including a run of 667 minutes when their goal remained unbreached, a run that came to an end in Saturday's 5-1 derby mauling of Espanyol. The worrying thing for opponents is that, in Alves's opinion, Barcelona can still get better.

"This team has no ceiling to its improvement," said the Brazilian right-wingback. "We've been showing on the pitch how we've got better. We found it hard to finish games off at the start of the season. Now we are on a great run, although we have to keep our feet on the ground."

We are on the right track to being able to compete and nothing is going to distract us. With Barça, nothing is impossible.
Dani Alves on Barcelona's chances of repeating their six-trophy haul of 2009 next year

Tomorrow's encounter pits the two most successful sides in Copa del Rey history against each other - Barcelona having 25 crowns to Athletic's 23 - and is a repeat of the 2009 final, which the Catalans won 4-1. That triumph was one of a record-breaking six trophies the club won in that year and, although there is a long way to go yet, Alves is not ruling out a repeat in 2010/11.

He added: "There's no harm in dreaming and with this team anything is possible. We are on the right track to being able to compete and nothing is going to distract us. With Barça, nothing is impossible."

Barcelona's cause against Athletic has been helped by the injured-enforced absence of the Basque side's star striker Fernando Llorente, although Alves insists their opponents are no one-man team.

"He's an important and vital player for them, but Bilbao are much more than just him," he said. "It's a tough tie. There are two games and everything won't end on Tuesday, there's still a second game to come and we are just looking to play well."