Jesus Arellano has had his suspension cut to one game, allowing him to play in at least two games in the World Cup.
Arellano, 29, who caught the eye when used as a second-half substitute during France 98, initially lost an appeal against a three-match ban.
He expected to be ineligible to play against Croatia and Ecuador.
The left-sided midfielder, was sent off during Mexico's World Cup qualifier against Costa Rica.
He was banned for three matches and missed the qualifier against Honduras.
But world governing body Fifa have now decided that the ban was too severe - and the player will miss only one more match.
"We never lost hope and we are very happy," coach Javier Aguirre told the press in Mikuni, Japan.
Arellano is a key member of the national team and Aguirre chose to take him to the World Cup even though he might only have played a single game.
"This changes all my prospects, I was so happy I couldn't sleep," Arellano said.
Another midfielder, Johan Rodriguez, will also miss the opening match against Croatia on 3 June because of suspension.