The Brazil international has not featured in Barca's pre-season schedule so far after suffering a back injury during his nation's 2-1 quarter-final win over Colombia at the World Cup last month.
The 22-year-old forward returned to training last week, however, and he could now feature at Camp Nou against the Mexican side when Barca battle for the Joan Gamper Trophy.
In a further boost, the club also confirmed that Xavi is free to feature after he suffered a calf strain in training at the beginning of August.
"The first team squad trained this morning ahead of the Joan Gamper Trophy at the Camp Nou against Club Leon," read a statement on Barca's website.
"At the end of the session, club doctors gave Neymar and Xavi Hernandez the medical all clear and both will be available for the game."
The fixture marks Barca's final pre-season match before their Liga opener at home to Elche on Sunday.