Rovers have completed the signing of central defender Joseph Olowu on a deal until January 2022.
The 21-year-old arrives at the Keepmoat Stadium to add defensive cover with Tom Anderson and Cameron John currently on the sidelines.
Olowu came through the ranks at Premier League side Arsenal, where he played alongside current Rovers loanee Matt Smith.
He was released by the Gunners earlier this summer and has since spent time on trial with Manchester United.
The Nigerian-born defender will wear the No.5 shirt during his time with Rovers.