A photo on Wayne Rooney’s social media pages showed Kai, 11, signing a deal with a ‘Rooney 10’ jersey next to him.
“Pride day. Kai signing for Man Utd [sic]. Keep up the hard work of sons, ”Wayne said, with his wife Colleen also pictured.
Coleen Rooney wrote on Instagram: “Special night… .. congratulations Kai. I love you and I am so proud of you. Keep doing your best. ”
Rooney, currently the acting Derby boss, became United’s all-time leading scorer after spending 13 years at Old Trafford.
The striker has scored 253 goals in 559 games, winning five Premier League titles, a Champions League, a Europa League, an FA Cup and three League Cups.
The former England captain signed for United from childhood club Everton in 2004, and left in 2017 upon returning to Goodison Park for a season before joining DC United.
After two years in MLS, Rooney returned to England to play for Derby in 2019, and after replacing Phillip Cocu sacked to temporarily take over the league in November, the 35-year-old has said he is ready to continue. . as a player if another manager is recruited permanently.
Rooney has stated his desire to take over the club full time, but admitted the possibility of an interview was unlikely until the new owners arrived.
Derby are undefeated in their last six games, earning two wins, although they remain in the relegation zone after 19 games played. A takeover remains on track to be completed before Christmas.