Ansu Fati and Pedri are the best Spanish players of their generation, according to Under-18's head coach Pablo Amo.
Fati is currently enjoying a breakout season at Barcelona, scoring three goals in 15 appearances across all competitions.
The 17-year-old featured regularly at the start of the campaign - with Lionel Messi out injured at the time - and became the youngest Champions League goalscorer in the history of the competition when he netted a late winner against Inter in December.
His superb performances earned him a call up to Spain's U21 squad, and he has been tipped to graduate to the senior setup if he continues on his current trajectory.
Pedri, meanwhile, is due to officially become a Barcelona player in June, with a deal that could end up being worth €15 million (£13m/$17m) already in place with his current employers Las Palmas.
The attacking midfielder - who is also only 17 - has scored three goals and laid on four assists in 19 Spanish Segunda outings for Las Palmas this term, displaying confidence and maturity belying his tender age.
The teenage pair won't be a part of Amo's squad for the upcoming Atlantic Cup, however, which marks the new manager's first tournament since taking charge of the U18s in December.
When asked to explain Pedri's absence, Amo told Marca: "He is [the best] player of his generation just like Ansu Fati, who also won't be there either.
"At club level, he is an important footballer, who will be in the following squads, although in a higher category than mine. I was pleasantly surprised the first time I met with him.
"When you see the boys playing together, in this case, Pedri in the World Cup, he participated with the U17s and became a leader, a reference point, who worked and sacrificed himself; a very humble boy.
"In that sense I wish him to continue in this way, with his feet on the ground, because conditions are promising."
Amo added on the teenage pair's continued developments this season: "One thing is the sporting aspect and another is the emotional and personal development that the boys have.
"They are mature players, as Ansu is with Luis de la Fuente at the U21 level and Pedri is in the pre-list of higher categories. We have to see how the season unfolds. They have to be lucky with injuries because they will give us a lot to talk about."
Fati will be back in contention for a place in Barcelona's squad when they travel to Mestalla to face Valencia on Saturday afternoon, while Pedri is likely to feature for Las Palmas when Tenerife arrive at Estadio Gran Canaria later that evening.