[6] On 10 August 2018, Mbulu signed a one-year contract with Motherwell after his release from Millwall at the end of the previous season.

[8] Mbulu made his league debut for Motherwell on 11 November, when he came on as a second-half substitute in the 77th minute of a game against Rangers at Ibrox.

[10] On 30 October 2019, Mbulu signed a short-term contract with Crewe Alexandra[11] until January 2020,[12] making his debut in an EFL Trophy tie against Everton U21s at Gresty Road on 5 November 2019.

[20][21] His team placed a picture of him on the substitutes bench during a visit to Chelsea in the FA Cup in January 2021 and at the Wembley play-off final against Newport in May 2021.

[22] Following his death the Christian Mbulu Trust was subsequently setup in his memory to empower, guide and assist young people in their own journeys through life.