The clash occurred in a tunnel leading from the playing field to the locker room area in the stadium.
Police said Langkilde was accused of assaulting two players, one a 26-year-old who sustained facial injuries and the other a 21-year-old who suffered broken facial bones, police said.
A third Wales victim, 24, also sustained facial injuries.
Langkilde was taken into custody at his San Francisco hotel on Sunday. Police said the investigation was ongoing.
(Reporting by Frank Pingue in Toronto; Editing by Ian Ransom)
