Barcelona need to maintain their focus till the end of games to ensure they stop dropping points in matches they should have won, coach Hansi Flick said on Saturday, after his team slipped to third in LaLiga due to a four-match winless streak.

Barcelona, who host 19th-placed Valencia on Sunday, were held 1-1 at Getafe last weekend despite dominating possession and having twice as many shots as their hosts.

"In Getafe it was our fault, that we didn't finish the game with the three points, we didn't play very well, we weren't focused. That has to change," Flick told reporters.

"We have to be focused from the start and until the end."

Barcelona bounced back with a 5-4 win at Benfica to reach the last 16 of the Champions League on Tuesday, but Flick is expecting a tough game against relegation-threatened Valencia, who are unbeaten in their last four matches in all competitions.

"We are well prepared. Valencia have stabilised their defence and they know how to play. It will be a demanding game for us. Their defence is very good... it won't be easy," he added.

Flick said there could be changes in the squad after the midweek trip to Portugal.

"We need fresh legs tomorrow... we have a few changes in the team and we will see," the German said.

"For me it's very important to win every game. And that's how we want to approach it. We always think about the next one. After Valencia, we'll see against Atalanta."