Barcelona have revealed that Pedri is facing a spell on the sidelines with a thigh injury that he picked up during a training session on Thursday morning.
The 20-year-old has started both of his team's La Liga matches this season, and he was on the scoresheet in the 2-0 success over Cadiz last weekend.
Pedri is now unlikely to be seen until October, though, with the La Liga champions revealing that the Spain international has "sustained a right quadriceps injury".
"FC Barcelona first-team player Pedri has sustained a right quadriceps injury. He is unavailable for selection and his recovery will determine his return," read a statement on Barcelona's official website.
Xavi's side have not put a timeframe on his recovery, but according to journalist Toni Juanmarti, due to the nature of the damage, he could be on the sidelines for more than a month.
The area of the injury will be concerning to Barcelona, as he spent time on the sidelines with two separate muscular problems last term, which were both on his right thigh.
Pedri will definitely miss his side's next two games against Villarreal and Osasuna ahead of the September international break, while he is also set to be sidelined against Real Betis, Celta Vigo, Mallorca and Sevilla in the latter stages of next month.
Depending on his recovery, the youngster, who has made 111 appearances for the club in total, could potentially be available to face Granada at the start of October.
Barcelona are already missing Ronald Araujo with a hamstring problem, with the defender also potentially being out of action until the early stages of October.
Raphinha is also still suspended, with the Brazil international set to serve the final game of his two-match suspension against Villarreal on Sunday afternoon.
Inigo Martinez has made progress in his recovery from a foot issue, though, with the summer arrival potentially being included in the squad for the clash with the Yellow Submarine.
Barcelona have picked up four points from their first two La Liga matches of the season, playing out a 0-0 draw with Getafe in their campaign opener before beating Cadiz 2-0 last time out.