* Mexico's Montes breaks leg, will miss World Cup
* Ecuador's Castillo doubtful after knee injury (Confirms Montes out of Brazil finals)
May 31 (Reuters) - Mexico beat Ecuador 3-1 in a friendly in Dallas on Saturday but the win was overshadowed by a broken leg for Luis Montes that has ruled the midfielder out of the World Cup finals.
Ecuador's squad may also be impacted by the incident, with midfielder Segundo Castillo carried off the pitch with a suspected knee injury.
Just two minutes after the livewire Montes had put Mexico ahead, he and Castillo slid into a 50-50 challenge and it was quickly apparent the Mexican had suffered a serious injury.
Montes was carried off on a stretcher and taken to a nearby hospital with Mexico coach Miguel Herrera later confirming he had suffered a broken tibia and fibula.
"It's the tibia and fibula and he'll have to have an operation which won't be at all easy," Herrera told the post-match news conference.
Some Mexican players were in tears after watching Montes writhe in agony while he was receiving treatment on the field - and that was not the end of El Tri's injury torment.
Herrera was also concerned about a foot injury suffered by captain and central defender Rafa Marquez who was also sent to hospital for further examination although he later said it was not too serious.
"We'll wait, in fact he could move his foot very well with a little pain but there were no signs of anything worse... (but) we must rule out everything and not take risks," Herrera told TV Azteca at the end of the match.
Away from the injuries, the game, played in front of 84,876 fans at the home of the NFL's Dallas Cowboys, showed again that Mexico have rediscovered their mojo under Herrera.
After a poor qualifying campaign, El Tri are now unbeaten in eight games under Herrera, including Wednesday's 3-0 win over Israel that began their warm-ups for Brazil.
Mexico led 1-0 at the break thanks to a superb 25 yard drive from Montes and they had played some entertaining football prior to his injury.
Ecuador, though, twice came close to equalisers in the second half - Fidel Martinez had a goal disallowed following a goalmouth scramble in the 62nd and a minute later a Joao Rojas effort was cleared off line by Mexico defender Paul Aguilar.
But a spectacular blast from 30 yards from Marco Fabian doubled Mexico's lead in the 69th minute, the midfielder finding some space before unleashing a fierce drive.
Seven minutes later the game was put beyond Ecuador when Giovani dos Santos shot against the post and the ball rebounded into the net off the back of Ecuador keeper Maximo Banguera.
Ecuador, whose defence had looked shaky throughout, did restore a little pride with a low free kick from Enner Valencia which skidded through a crowded penalty area.
At the tournament starting on June 12, Mexico will face Cameroon, Brazil and Croatia in Group A, while Ecuador are in Group E with Switzerland, France and Honduras. (Reporting By Simon Evans; Editing by Rex Gowar/Nick Mulvenney)