"Great few days in Coleraine for the Super Cup NI," Rooney captioned his Instagram post. "Well done to Kai Rooney and the Manchester United lads on a brilliant effort throughout the tournament. Congratulations to Southampton on the win. Thanks to everyone for the warm welcome."
A few days earlier Rooney had reflected to BBC NI about his own time playing at the tournament, and the nature of his role in Kai’s fledgling career.
"It's a long time ago since I was here but it does bring back great memories," he said. "The Super Cup, like many other tournaments, is a fantastic place to go away as a young person. You're away with your teammates in a hotel together and it's great for team building.
"[Kai] has great coaches at Manchester United, so I take a stand off approach. I speak to him, but for me it's all about his mentality and his mindset, to make sure he keeps enjoying it, that's the main thing for me."