Croatia, May 14 -- Cristiano Ronaldo said he was "very proud" of his eldest son after he made his debut for Portugal Under-15s.

Cristiano Ronaldo Jr came on in the 54th minute of a 4-1 win against Japan in a tournament Croatia on Tuesday.

The 14-year-old was watched on by grandmother Dolores Aveiro, Ronaldo Sr's mother.

It was also reported, external that scouts from Manchester United - a former club of Ronaldo Sr - and several other top European clubs were in attendance to watch Ronaldo Jr, the BBC reported.

Five-time Ballon d'Or winner Ronaldo Sr said on Instagram: "Congratulations on your debut for Portugal, son. Very proud of you."

Rafael Cabral scored a hat-trick for Portugal before Ronaldo Jr came off the bench.

Ronaldo Sr, 40...