Birmingham City and Charlton Athletic drew blank with "highly-rated" Chelsea transfer | OneFootball

Juan Familia-Castillo only managed 8 appearances between the two EFL sides when on loan.

Former Chelsea left-back Juan Familia-Castillo's brief loan spells at Birmingham City and Charlton Athletic in the 2021/22 season were a nightmare for all involved.

This was surely a surprise though, given the Amsterdam-born defender progressed through Ajax's renowned youth system before joining Chelsea in 2016.

He then helped Blues' academy win the U18 Premier League and back-to-back FA Youth Cups.

Even before his two temporary spells in the lower tiers of England, Familia-Castillo made 17 first-team appearances for Eredivisie outfit ADO Den Haag, with 16 of those coming in the Eredivisie, highlighting just how highly regarded a prospect he was.

Considering these two points, and the fact he had captained both Ajax and the Netherlands at various age groups, the wing-back was a very attractive proposition on paper - but he more than failed to live up to the hype.

Lee Bowyer dropped concerning Juan Familia-Castillo claim at Birmingham City - he also backed him for Chelsea success

Perhaps the most damning assessment of Familia-Castillo's Blues stint came from ex-Charlton favourite Lee Bowyer, who was managing Birmingham at the time.

Speaking to Birmingham Live in 2021, Bowyer revealed the stark reality of the situation: "When he first came he was overweight, couldn't run, broke down in the first week or two of preseason because he was out of shape."

Bowyer did mention the defender's qualities though, and was hopeful the West Midlands side could change his fortunes.

"He is very quick and direct. Juan has strengths and weaknesses, like every player.

"He is another one that I believe when he goes back to Chelsea, we will have improved him, and he will be a better player," Bower added.

However, the Chelsea loanee's struggles at St Andrews were evident in his limited playing time. Despite arriving for the full season, Familia-Castillo managed just five appearances for Birmingham, with only one league start coming against QPR on 2 January.

The thing is, his debut came as a substitute in the opening day win over Sheffield United, but it would take another three months before he featured again - showing how far he had fallen down the pecking order from the likes of Kristian Pedersen and Jeremie Bela.

Football League World's Birmingham City fan pundit called him the flop of the season in April 2022, noting that the wing-back didn't look like a "natural footballer" or have any confidence on the ball at all.

Chelsea made the decision to recall Familia-Castillo from Birmingham and immediately send him to Charlton in January 2022, and it was definitely an attempt to give him more game time in a familiar environment, but it didn't work.

The Addicks had built a reputation for successfully developing Chelsea loanees, with previous success stories including Conor Gallagher, Jay Dasilva and Ian Maatsen respectively.

The former had scored six Championship goals and provided two assists when an Addicks player during the 19/20 season. Their recruitment director, Steve Gallen, mentioned this swayed Familia-Castillo to join the club.

Yet Familia-Castillo's time at The Valley proved even more limited than his Birmingham stint. The defender managed just 98 minutes across two League One appearances for Charlton - which were against Wigan Athletic and MK Dons.

Then-Charlton owner Thomas Sandgaard was seemingly very excited about the signing, which makes the lack of game time in south-east London disappointing.

Sandgaard told the club's website, "We have been wanting to add a player with speed and attacking qualities to compete for places in the left wing back role.

"Juan matches that profile and is highly-rated at Chelsea," Sandgaard continued.

But, it's fair to say that - like in Birmingham - he ended up being the opposite of highly rated. With one Addicks fan taking to social media to list him, among others, as one of the worst left-backs the club's ever had.

After leaving Chelsea permanently at the end of the 22/23 season when his contract expired, Familia-Castillo spent a year away from the professional game before signing back in Holland for RKC Waalwijk in June 2024.

While switching his allegiance to the Dominican Republic, he played 24 times in the Dutch top-flight during the 24/25 season as RKC were relegated.

There's no denying that he was probably expected to go on to much better things as a youngster, but ultimately, both Birmingham City and Charlton Athletic drew a blank with their Chelsea loan gamble.

Bowyer's words about the player being overweight suggest the due diligence on Familia-Castillo wasn't properly conducted before the club signed him, which only added to their problems in what would prove to be a Championship relegation battle for the club that year, in which they survived from, finishing 20th.

Talent alone wasn't enough to warrant Johnnie Jackson playing him at Charlton either, and he was the only one out of the previous three Chelsea loanees in the recent time before him to not make a meaningful contribution.