Chelsea are still adapting to life under Maurizio Sarri and are currently fourth in the Premier League table. Their primary objective this term is to finish in the Champions League qualification places, while also looking for domestic success in cup competitions.
However, the Blues need to make some important improvements within their senior side if they're to achieve their goals - Sarri could use the existing January transfer window as an opportunity to further enhance his squad.
With that in mind, here's a list of three signings who could help Chelsea finish in the top four places this season:
#3 Jonathan Tah (Bayer Leverkusen)
Chelsea have done a decent defensive job so far this season and conceded just 17 goals in the opening 22 Premier League games. However, with David Luiz and Gary Cahill's contracts set to expire at the end of this season, it's clear they need a new central defender to maintain their defensive stability.
Bayer Leverkusen's Jonathan Tah is one of the world's best young defenders and would be a great signing for the west Londoners. The 22-year-old is blessed with great reactions and can recover from any position. His huge frame, standing over 6ft 5in helps him to steal the ball away from attackers - using his rapid pace to eradicate counter-attacking threats.
The youngster has made 108 Bundesliga appearances and 123 total matches since joining Leverkusen in the summer of 2015. He also became a full Germany international in 2016, with four caps to date. Tah was previously linked in the past with a move to England's top-flight, and they could again turn their attention towards him.
Despite this though, his current contract with his parent club will run until 2023 and they might have to pay a premium to convince Leverkusen into selling one of their prized assets.