#3 Marc Cucurella | Getafe
Marc Cucurella was at La Masia for over five years before being sent out on loan spells to Eibar and Getafe by the Blaugrana. After Eibar signed him, the club purchased him back only to send him out on loan to Getafe just over two weeks later, after which the Madrid-based club signed him permanently.
The 22-year-old has put in some incredible shifts for Getafe this season. Playing as a defensive-minded left-midfielder in a 4-4-2 with Mathias Olivera behind him, Cucurella's defensive numbers make for excellent reading as he puts in 2.17 tackles and two blocks a game. No player in LaLiga has registered more pressures than Cucurella's 654 this year, and he's also made the ninth-highest number of tackles.
The Spaniard's all-action approach down the left-hand side could be a great addition to Koeman's system that demands players to bomb up and down the pitch in wide areas. If Barcelona can convince Cucurella to return to the Nou Camp, he could be a superb option to replace Alba with.
#2 Alejandro Grimaldo | SL Benfica
Spanish full-back Alejandro Grimaldo is another player who was on Barcelona's books for a few years before ultimately departing the club in order to gain valuable minutes in Europe. Grimaldo left for SL Benfica in 2016 and has been one of the best offensive-minded full-backs in Europe since breaking into their first team.
The 25-year-old has appeared just under 200 times for Benfica since leaving Barcelona, racking up 13 goals and 39 assists for them in this period. Grimaldo currently leads Liga NOS' assist charts with eight to his name and averages a stunning 10.84 progressive carries per 90, one of the highest figures for full-backs across Europe.
Grimaldo is contracted to Benfica up until the summer of 2023, but given that the left-back slot at Barcelona could finally be up for grabs, bring Grimaldo back to the Nou Camp could be an excellent option for all parties involved.
#1 Jose Gaya | Valencia
Jose Gaya is, by all accounts, the most ideal player for Barcelona to replace Jordi Alba with. The Spanish international has amassed a wealth of experience playing in LaLiga Santander as he's racked up 205 league appearances for Los Che, scoring five and setting up a further 22.
Gaya has all the tools to succeed as a modern full-back as he's a dependable crosser and has improved the defensive side of his game remarkably over the years. The Valencia captain is a tenacious full-back who chases down wingers on his side of the pitch, endearing himself to the Los Che faithful with his style of play. He averages nearly two tackles per 90 in the league, and only five LaLiga players have managed more crosses than he has.
While Gaya might not be the superstar he was tipped to become when he first broke onto the scene, he is arguably the best option for Barcelona to pursue in the transfer market as a long-term successor to Jordi Alba. He has his best years ahead of him while also boasting of a great amount of experience in Spain, making it an ideal combination. Gaya is contracted to Valencia until the summer of 2023.
Also read: Top 5 left-footed centre-backs in world football