The attorney general's office in the state of Puebla said the attack occurred yesterday in the town of Acatzingo, 170 kilometers (105 miles) from Mexico City.
"According to witnesses, three vehicles arrived, the occupants dismounted and opened fire. They opened fire equally against players and the public," said Jesus Jimenez, Acatzingo's Director of Security.
Jimenez said both of the dead were players, one of whom died on the playing field and the other as he was being rushed to the hospital.
Two local teams -- Reyes de Juarez and Felipe Angeles -- were playing against each other in the finals of an amateur league.
Puebla is one of the Mexican states that has largely been spared the drug cartel violence afflicting other parts of the country.
But it has had a high incidence of vigilante violence, as well as criminal activity centered on the theft of fuel from the facilities of state oil giant Pemex.