Rosenior arrives from Strasbourg to replace Enzo Maresca, who left on New Year's Day after his position became untenable, with Chelsea already considering a change. Despite having managed fewer than 100 senior matches and never coaching in the Premier League, Rosenior insisted he is ready for the challenge.
"This is a club with a unique spirit and a proud history of winning trophies," Rosenior said. "My job is to protect that identity and create a team that reflects these values. To be entrusted with this role means the world to me."
The former Hull City boss confirmed his impending move earlier this week, describing Chelsea as "one of the biggest clubs in the world". Both Chelsea and Strasbourg are owned by the BlueCo group led by Todd Boehly and Clearlake Capital.
Rosenior guided Strasbourg to seventh place in Ligue 1 last season, securing European football for the first time in eight years. He leaves the French side seventh domestically and top of their Conference League group, although their latest match was a 1-1 draw at Nice, extending a five-game winless league run. Strasbourg staff members Kalifa Cisse, Justin Walker and Ben Warner will join him at Stamford Bridge.
A former defender with spells at Fulham, Reading, Brighton and Hull City, Rosenior retired in 2018 and moved quickly into coaching. He almost led Hull to the Championship play-offs in 2024 before taking over at Strasbourg last summer.
Caretaker manager Calum McFarlane will oversee Wednesday's Premier League match at Fulham following a 1-1 draw at Manchester City. Rosenior is set to take his first training session on Thursday and will be in charge for Saturday's FA Cup third-round tie away to Charlton Athletic.
Crystal Palace manager Oliver Glasner has confirmed the club would consider selling captain Marc Guehi during the January transfer window if their valuation is met, with Manchester City weighing up a move for the England defender.
Enzo Maresca has spoken publicly for the first time since leaving Chelsea on New Year's Day, less than six months after guiding the club to Club World Cup success, subtly hinting at tensions with those in charge.
West Ham's slide towards relegation deepened after a dramatic late collapse handed Nottingham Forest a crucial 2–1 victory, decided by a VAR-awarded Morgan Gibbs-White penalty in the closing minutes.
Newcastle head coach Eddie Howe has firmly ruled out any move to Manchester United, reaffirming his contentment at St James' Park despite speculation linking him with the Old Trafford vacancy following Ruben Amorim's departure.
