Barcelona must be ruing their decision to let Dani Alves go last summer.

The Brazilian joined Juventus after eight years at the Nou Camp and handed the Blaugrana a timely reminder of his worth by helping to knock them out of the Champions League.

That will have been particularly painful for Barca to take, but they must have already been aware of the impact the full-back's departure has had on their hopes of silverware.

Luis Enrique has never properly replaced the 34-year-old.

Aleix Vidal and Sergi Roberto have not convinced, and the club are therefore expected to make signing a new right-back one of their priorities when the transfer window opens.

Arsenal's Hector Bellerin is set to be one of the players at the top of their wish list.

Mundo Deportivo report that Barca's technical secretary Robert Fernandez was sent on a scouting mission to watch the defender in the Gunners' 2-0 win over Manchester United, though he'll have been disappointed as Bellerin only came on as a substitute for Alex Oxlade-Chamberlain with six minutes left.

Sunday afternoon's game is unlikely to have convinced Barcelona of his credentials, but it's quite possible a deal could go ahead anyway.

Bellerin is keen

The same source have suggested that the 22-year-old is open to returning to his former club because he thinks it will boost his chances with Spain. It's going to be easier for him to catch the eye of Julen Lpetegui, the national team manager, from La Liga, and he won't want to miss out on next year's World Cup.

Barca is also an appealing option because rather than link up with Pep Guardiola at Manchester City, Bellerin would rather move to a club outside the Premier League so he doesn't feel he is betraying Arsenal.

Bellerin is one of the most highly-rated full-backs in the country, but he hasn't been first-choice since Arsene Wenger switched to a back three.

Wenger may or may not persevere with that system, but he may have inadvertently opened Bellerin's eyes to the benefits of swapping north London for Catalonia.

Is Bellerin good enough to replace Alves? Have your say in the comments.