Mexico and Ecuador will be missing key player in their upcoming campaign at the 2014 FIFA World Cup in Brazil, which is set to kick off on June 12.

Mexico will head to Brazil without midfielder Luis Montes, while Ecuador will miss midfielder Segundo Castillo after the two of them were involved in a disastrous incident during their friendly in Arlington, Texas.

Montes, who is considered as one of the key players for Mexico in their upcoming World Cup stint, collided with Castillo, which led to a gruesome leg injury.

Tests revealed that Montes sustained a broken fibula and tibia in his right leg.

"It hit them very hard," Mexico coach Miguel Herrera said of his player's reaction on Montes' injury via Dallas Morning News. "Everyone was on the sideline. A few were crying, tears in their eyes. It was a tough situation."

Losing Montes is a huge blow to their campaign, but Herrera expressed optimism that his players will be up to the task in Brazil this month.

"Right now we're not thinking about the next games. Right now we want to have a good talk with the players. It's an unfortunate situation, and we have to keep moving forward," Herrera said.

Montes' gruesome leg injury overshadowed the fact that Castillo was also hurt after the collision.

Castillo was seen holding on to his knee after the clash, and it turned out that Castillo will also miss the World Cup after being diagnosed with a torn ACL after the match.

Ecuador coach Reinaldo Rueda said that Montes' challenge was "imprudent", adding that seeing two key players missing the World Cup due to an incident in a friendly is very unfortunate.

"I didn't see (the play) but I believe there was a bit of precipitation in that 50/50 ball," Rueda said. "It's unfortunate that this occurs because it is now a streak of two or three World Cups in which national teams lose important players."