Atsu's professional career began at Porto before leaving for Chelsea in September 2013, and he will be at St James' Park to watch the last-four tie.
"I was lucky to play with great players like Hulk, (Radamel) Falcao, Jackson Martinez, James Rodriguez, and I learnt a lot there," he told Newcastle's official website.
Atsu believes Newcastle's academy is comparable to that of the Portuguese club, who beat Sunderland 5-0 to win the 2016/17 International Cup final.
"An example is Paul Dummett. "We are very happy with him, so he shows that there are great players in the academy and they can also make it to the first team.
"I've trained with some of [the current under-23 players] also. They have great talent and I believe most of them can break into the first team if they really want to, and continue working hard.
"Porto is a team that loves to keep the ball, they work hard and they try to press the opponents every time. I think it will be a very good experience for them to pay against teams outside England, to see how other teams play. They will learn a lot."
The winners will face Arsenal in the final.