The Brazilian, a midseason arrival from Palmeiras, hasn't played since breaking his foot in February.
But after surgery and an intense rehabilitation period the 20-year-old has come on leaps and bounds in recent weeks and could feature at Wembley on Sunday.
Indeed, Guardiola refused to rule out the youngster even starting the game against the Gunners.
“He is really much, much better,” the City manager said. “Today, he makes part of training with us.
“He’s coming back with his happiness and we are so happy he is back again.
“We are going to travel, all the squad, to Wembley. He will be part of that. After we will see.”
John Stones will miss the game with what Guardiola described as a "muscular injury" but the rest of the squad are in good shape as they bid to progress and keep Guardiola's hopes of a trophy in his first season at the Etihad alive.
“All the squad is going to travel for Sunday tomorrow afternoon, quicker than normal to arrive in time to see the first semi final all together," he added.
“After we will be all together and after dinner we will decide the team and the people on the bench.”