The centre-forward has agreed a deal with the Club that will run until summer 2029, and will wear the number 36 shirt.
Born in Gödeken, Argentina, Alejo joined Rosario Central at Under-20 level and progressed to make his first team debut in July 2021. The 19-year-old attacker made a total of 62 appearances for the Primera Division side in all competitions, scoring 19 times.
On the international stage, Alejo featured for Argentina at the FIFA Under-20 World Cup and Under-20 South American Championship earlier this year. He has scored three goals in nine appearances at that level to date.