The youngster has previously spent time on trial with Manchester United and Arsenal and has also been linked with Italian giants Inter Milan.
“I believe my playing style is better suited to Portugal,” Grey told Sportbladet. “I am a bit nervous but I believe it will go well.
“They (Porto) say they have seen good technique, but nobody with my playing style.
“I am quite big, but I have good technique and a good left foot.”
