Romero, who has played two World Cups, has been replaced in the World Cup squad by Nahuel Guzman, who plays in Mexico for Tigres UANL, reports Xinhua news agency.
Romero's injury will be seen as a huge blow to Jorge Sampaoli's side, with his experience likely to have been valuable to a team looking to cast doubt on the under-performing label often attributed to their performances at major tournaments.
The 31-year-old requires surgery to correct a long standing knee problem.
"I was going to begin my rehabilitation. But the team wanted a goalkeeper who could train with them every day and they excluded me," Romero said.
Romero, who acts as understudy to David De Gea at Manchester United, was expected to be Argentina's first-choice keeper once more, having started in the World Cup final defeat to Germany back in 2014.
Speaking to TyC Sports from Barcelona, Romero added that it was "a very old injury," dating back to an operation in 2004, when he played for the Racing Club at the age of 17.
"A fragment of cartilage was loose in the knee and it had lodged itself in the back of the knee. It let me play championships in the Netherlands, Italy, France and England, I played two World Cups," he said.
Romero, 31, said that he received a knock from Diego Costa during a friendly with Spain on March 27, where Argentina lost 1-6.
This "destabilized the knee" and worsened his pain. The goalkeeper, who has won 94 caps for Argentina, said he has no ill-feeling toward national team head coach Jorge Sampaoli.
"On the contrary. I hope all goes well with the team. I wish it (the team) well, not only because I have great friends there," he explained.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
