Barça has set the wheels in motion to strengthen the squad for next season and is very clear that they want to sign a left winger. Deco and Hansi Flick have agreed in identifying this position as the absolute priority for the summer transfer window.

At the moment, Barça only have Lamine Yamal and Raphinha as natural wingers in the squad. The lack of alternatives on the left has limited the options. For this reason, they are looking to bring in a player capable of creating top-level danger who can compete with them.
Marcus Rashford and Luis Díaz top the list
The two names on the list are Marcus Rashford and Luis Díaz. Both possess the characteristics the club is looking for, and Deco is still studying their options.

Marcus Rashford remains a highly valued player in Barça's circle. His versatility to play both as a winger and as a center forward makes him especially attractive. Meanwhile, Luis Díaz has been one of Liverpool's standout figures, and his intensity, competitive character, and ability to break lines make him an ideal profile.
Guardiola offers an unexpected alternative
Although Rashford and Luis Díaz are the top options, the sporting management is also considering other alternatives. Among them, an unexpected option has emerged from Manchester City. According to sources close to the English club, Pep Guardiola would be willing to let Jack Grealish leave.
Grealish, who arrived at City as one of the most expensive signings in their history, hasn't managed to establish himself as an undisputed starter. Guardiola would welcome his departure if a reasonable offer comes in, and has offered the player to several clubs, including Barça. From the footballer's circle, there is also a willingness to seek a change of scenery and look for new challenges.
Grealish's profile doesn't fit Barça's plans
However, despite being an attractive market opportunity, Jack Grealish doesn't quite fit what Barça are looking for. The priority is to bring in a profile with more explosiveness and verticality, something neither Grealish nor his more associative and measured style offer.
Barça want a destabilizing winger, someone who can take on defenders and create advantages through dribbling, a style that fits much better with Luis Díaz or Rashford. Everything indicates that the club will focus its efforts on securing the arrival of a more direct, more electric player with greater ability to break through defenses.