Teden Mengi has become the latest Manchester United youngster to sign a new long-term deal at Old Trafford.
Academy product Mengi, who made his senior debut in last season's Europa League against LASK Linz, is set to stay at the club until at least 2024, with an option for an additional 12 months in his contract.
United legend Rooney, now Derby manager, used his connections at Old Trafford to bring Mengi to Pride Park on loan in January, giving the centre-back an opportunity to get first-team minutes in the Championship.
So far there have been six appearances for the Rams, including four starts in the Championship.
Mengi is the third United youngster to put pen to paper on a new deal in the space of as many days, following in the footsteps of fellow 18-year-olds Hannibal Mejbri and Anthony Elanga. Shola Shoretire signed his first professional deal with the club last month.