The 11-year-old, who is the oldest of Rooney’s four sons, has joined the academy at the club where his father is the all-time record goalscorer.
Rooney posted a picture on social media with Kai and mother Colleen, writing: “Proud day. Kai signing for Manchester United. Keep up the hard work son.”
Wayne himself joined United at a young age, arriving from Everton as an 18-year-old, and going on to score 253 goals in 559 appearances during a 13-year stay at Old Trafford.
The 35-year-old is currently interim manager at Championship side Derby County, though he has not yet called an end to his playing days.
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