La Liga could go to court to challenge FIFA's opposition to Spanish league games being played in the United States.
On Friday, the FIFA Council voiced its opposition to plans for Barcelona to play Girona in Florida on Jan. 26.
The proposal would need approval from the Spanish and American football federations, plus continental bodies UEFA and CONCACAF.
Speaking after a meeting of the council, FIFA president Gianni Infantino said it had backed the principle that "official league matches must be played within the territory of the respective member association."
FIFA is expected to confirm its position in writing to CONCACAF and the federations in the United States and Spain.
In a statement to The Associated Press, La Liga said: "Should we receive official notification from FIFA that they prohibit the match, we will take the case to the Court of Arbitration for Sport (CAS) with urgency."
Although CONCACAF and the federations in the U.S. and Spain had asked FIFA to make its position on the proposed match in the U.S. clear, the governing body's permission for the game to be staged there is not mandatory.
Last month, the president of the players' union, David Aganzo, said La Liga footballers remained unconvinced that plans for an overseas game are in their best interests.
But Tebas said: "Playing in the United States is vital to our strategy there and we won't relent on what is our right.
"If you want to make your industry more global, as La Liga wants to, if you want to be among the biggest industries in world sport, then you have to be immersed in the U.S. market."
If it happens, the Miami match would be the first to take place as part of a 15-year deal struck between La Liga and U.S.-based entertainment company Relevent to play one Spanish regular season game in the U.S. every year.