Barcelona sporting director Robert Fernandez has said the club will make "big-name signings" as they look to strengthen new coach Ernesto Valverde's squad.
After missing out on the Liga title to Real Madrid last season and losing to Juventus in the Champions League quarterfinals, Barca want to invest in players who can improve the team immediately.
Hector Bellerin, Marco Verratti and Ousmane Dembele are reported to be their three top targets as they look to add a right-back, a central midfielder and a forward.
But Arsenal, Paris Saint-Germain and Borussia Dortmund are not keen to sell, and there are doubts over Barca's ability to afford all three in the same window.
Former PSG director of football Patrick Kluivert has said the French club will not let Verratti leave for Barca this summer.
However, Fernandez told the club's official magazine: "We have a lot of information and there's a lot of work going on behind the scenes.
"It goes without saying that we'll bolster the squad in the positions we need and that they'll be big-name signings."
However, the sporting director said it had become increasingly difficult to convince players to come to the Camp Nou because of the intense competition for places.
Six new faces arrived last summer but, with the exception of Samuel Umtiti, none has yet been able to earn a regular place.
"The biggest difficulty we face is our own grandeur," Fernandez said. "A lot of players don't want to come here because they aren't sure they'll get much playing time.
"But we are very happy with the players that we signed last summer because we think that this year they will make big steps forward in their careers."
