Chelsea continue to be linked with left wing-backs this January as Thomas Tuchel aims to strengthen the position.
The German lost his first-choice option in November when Ben Chilwell was ruled out until the end of the season as a result of a ruptured cruciate ligament.
His season-ending knee injury has left Tuchel short of options, and the Champions League holders have been looking to find cover before the transfer window closes.
The Blues had explored the possibility of signing Lucas Digne but he sealed his move from Everton to Aston Villa in a deal worth £25million earlier on in this month.
They've also tried to recall Emerson Palmieri to Stamford Bridge but with no such agreement in the contract with Lyon, Chelsea have found it difficult to persuade the French club to permit his return.
Now, they're being linked with a move for Stuttgart's Borna Sosa.
However, according to Sky Germany, via the Metro, Stuttgart are holding out for a €30million (£25.1million) transfer fee for the Croatia international, which could put Chelsea off making a move this month.
Stuttgart are also reluctant to let Sosa leave as he is a key part of their team and they are currently in a relegation battle in the Bundesliga.
Nevertheless, as the 24-year-old isn't a household name just yet, who would Chelsea be getting if a deal were to be agreed?
Well, although Stuttgart are struggling in the league, Sosa is having a contrasting season.
With two goals and three assists in 18 appearances in what has been a poor side thus far, the Zagreb-born defender has shown his attacking capabilities, which is important in Tuchel's set-up.
He started his senior career at Dinamo Zagreb where he made his debut in a 2-0 home win over NK Zagreb in 2015.
Over the course of four seasons in his early career at Dinamo, Sosa made 41 appearances and registered six assists for his hometown club.
He signed a five-year-deal at Stuttgart in 2017 but suffered a number of injuries in his first couple of seasons. However, he thrived in Pellegrino Matarazzo's 3-4-2-1 system in the 2020-21 season and even earned comparisons to David Beckham, whom he named alongside David Alaba as his footballing idol.
Sosa ended that season with an impressive nine assists and has looked promising since.
He's also a full Croatian international, although his international career began with controversy.
Although he'd represented Croatia throughout his youth career, in May 2021, it was reported that he was given German citizenship as his mother was born and raised in Berlin, a fact that he later confirmed to Croatian newspaper 24Sata.
He was expected to represent Germany at Euro 2020 but it was later announced by Oliver Bierhoff - the German FA's technical director - that FIFA rules prevented him from playing for the Germans.
Sosa issued an apology to Croatian fans before making his debut against Russia in August, 2021.
