Barcelona star Jordi Alba has been a loyal servant to the Catalan gaints for almost a decade. The Spanish international has been one of the best in the world in his position for a few years now, and has won 15 major honours with the Blaugrana since moving from the Mestalla. However, having turned 32 last month, he doesn't have too many seasons at the highest level left in him. In fact, some would even argue that this is the case even in his current state, given that Alba has already missed 14 games this season due to muscle injuries and is no longer the energetic player he was in his prime.6 - @FCBarcelona's Jordi Alba 🇪🇸 has been directly involved in more goals than any other @LaLigaEN defender this season in all competitions (6, 1 goal and 5 assists). Critical. pic.twitter.com/TA2BRhfjxl— OptaJose (@OptaJose) December 16, 2020With Barcelona going through a gradual transitional period during which their veterans have begun to be phased out, Alba could potentially be next in line. The Blaugrana already parted ways with club legend Luis Suarez, and it would appear that Gerard Pique is also incapable of playing week in week out.Should Barcelona choose to bring in an able deputy for Alba this summer or the next to gradually reduce the burden placed on the shoulders of the Spanish full-back, they could find a host of options. Here, we take a look at five ideal ones for Ronald Koeman's side.#5 Juan Miranda | Real Betis (On loan from Barcelona)Real Betis v Deportivo Alavés - La Liga SantanderJuan Miranda serves as an in-house option to kick off this list as he's technically on loan from Barcelona. The Spanish full-back was sent out on loan to Schalke 04 last season, but it was a disastrous spell overall given the shambles that the German club were in. Nonetheless, Miranda was brought back to the Nou Camp and then sent to Real Betis, where he's had a much better spell.The 21-year-old is a La Masia product with an incredibly high ceiling. He's started 14 games this season for Los Verdiblancos and played in 18 league games overall, during which he's impressed both defensively and offensively. It is important to note that he is more of a traditional full-back rather than an offensive-minded full-back.However, Miranda is certainly more of a long-term option than the others on this list as he still has a fair bit of experience to gain before being thrown into the deep end at Barcelona and filling in for a veteran such as Alba. Miranda's contract is set to expire soon, so it remains to be seen if the club will extend it and whether they see a future for him at the Nou Camp. #4 Raphael Guerreiro | Borussia DortmundEintracht Braunschweig v Borussia Dortmund - DFB Cup: Second RoundRaphael Guerreiro has been linked with a move to Barcelona on numerous occasions in the past. The Portuguese star is a versatile player capable of playing at left-back or wing-back, and has been one of the most important attacking outlets for Borussia Dortmund over the last few years.With Ronald Koeman deploying a three-man defence that utilises wing-backs on a regular basis, Guerreriro's experience playing in this position could be of great significance. The 27-year-old has managed to rack up some superb attacking numbers this season, having registered five goals and nine assists in over 30 games for BVB.Raphael Guerreiro has scored three goals for Dortmund since the Bundesliga restart—from left wing-back 😳 pic.twitter.com/5de4HVIcWP— B/R Football (@brfootball) May 23, 2020The 2016 UEFA Euro winner is currently contracted to the Bundesliga club until the summer of 2023, so it remains to be seen if he will be available in the transfer market. However, should Barcelona sign him, he could be a superb player to help phase the ageing Alba out of the side.Also read: 5 Transfers that dramatically changed the fortunes of a club