The Unites States international opted to leave the Camp Nou last summer after failing to break into the La Blaugrana first team.
Ligue 1 side Marseille paid £2.5m to bring him to France ahead of the 2021/22 season with Barcelona retaining a 50% sell on clause on the 21-year-old.
After struggling with form and injury issues since the start of 2022, Marseille are now prepared to loan him out in the coming weeks, to reignite his career.
Valladolid have looked to rebuild their squad on a budget in recent weeks after securing promotion back to the top-flight from the Segunda Division.
José Rojo Martín’s side kick off their campaign at home to Villarreal on August 13.