Chelsea are reportedly ready to back new head coach Liam Rosenior by making up to three signings in the January transfer window. The Blues are looking to strengthen in a number of areas in a major show of support for their manager, who replaced Enzo Maresca in the Stamford Bridge dugout earlier this month following the Italian’s departure on New Year’s Day.According to a report from The Telegraph, Chelsea are looking to give Rosenior the extra tools he needs to reshape the side in his image. It's claimed the west Londoners are prioritising adding a new central defender to their ranks - something which they intended to do under previous boss Maresca, with the club losing out to Real Madrid when attempting to sign Dean Huijsen last summer.The six-time league champions are keen to land a new centre-back due to the long-term injury sustained by Levi Colwill in pre-season, while Wesley Fofana continues to battle fitness issues having previously suffered an anterior cruciate ligament (ACL) injury - as well as a broken leg - during his career.Chelsea are also believed to be monitoring targets in midfield and in attack ahead of the summer transfer window, though co-owners Todd Boehly and Clearlake Capital are ready to pounce if the right opportunities present themselves in the winter market.One man who Chelsea are reportedly paying close attention to is highly-rated Rennes defender Jeremy Jacquet, with Italian reporter Fabrizio Romano claiming the two clubs have held dialogue in the last 24 hours.However, Les Parisien journalist Benjamin Quarez is reporting Rennes have no intention of selling Jacquet this month, with Habib Beye’s side - who are currently sixth in Ligue 1 - in contention to qualify for European football next season. A separate report from French football writer Fabrice Hawkins claims Chelsea are ready to table a €50 million (£43.3m/$58m) offer to sign Jacquet this month.Looking for smarter football bets? Get expert previews, data-driven predictions & winning insights with GOAL Tips on Telegram. Join our growing community now!Emerging through a famed Rennes academy that has produced the likes of Ousmane Dembele, Desire Doue and Eduardo Camavinga, Jacquet is regarded as one of Europe’s most promising young defenders.The 20-year-old made his profession debut for Les Rennais in January 2024, emerging as a late substitute as his side defeated Nice 2-0. He subsequently joined lower-league side Clermont Foot on loan until the end of the 2023-24 season.Jacquet extended his temporary spell with Clermont until the conclusion of the 2024-25 campaign, only for Rennes to recall him in February last year. The France Under-21 international then signed a contract extension with his parent club until 2029.Add GOAL.com as a preferred source on Google to see more of our reportingWhile Jacquet remains Chelsea’s preferred target as they look to bolster their defensive options, the Daily Mail claims the club have drawn up a shortlist of alternative signings, in event that a deal cannot be agreed with Rennes this month.The report claims Chelsea are also admirers of Jacobo Ramon, 21, who currently plies his trade for Cesc Fabregas’ Como in Serie A, as well as Bournemouth centre-back Marcos Senesi, 28, who could be available for a low price due to his contract expiring in the summer.While it remains to be seen whether Chelsea are able to strengthen in their three preferred areas in January, they return to Premier League action when they entertain high-flying Brentford on Saturday.The fixture is Rosenior’s first league game in charge following his arrival from Ligue 1 side Strasbourg, having guided Chelsea to the FA Cup victory over Charlton Athletic last Saturday before the narrow Carabao Cup reverse against Arsenal on Wednesday.Speaking ahead of what he expects to be a stern test against Brentford - who are currently fifth and two points above the eighth-placed Blues - Rosenior said in his pre-match press conference: “They are a proper team in every phase of the game.“All 11 players are willing to defend. They're a very good team on set-plays, whether that's from long throws, wide free-kicks or corners. They're a team with no ego, in the most positive terms. They work really hard for each other, they're very well organised, as every team in the Premier League is.“We prepare for everything. There's no stone left unturned, not just from me, but from all of my staff. I'm aware of the threats that Brentford bring, and I'm sure they're aware of the ones that we do too. We know we will have to be at a really good level.”