Atlanta United’s Emerson Hyndman sustained a torn ACL in his right knee during a training session. The team announced the injury Thursday, but didn’t say when or how the injury occurred.

A statement put forth by the club said that Hyndman will undergo surgery at a date to be determined.

The team didn’t provide a timetable for Hyndman’s return, but it seems likely that he will miss the rest of the MLS season, based upon the rehab timetable of other players. Josef Martinez suffered a torn ACL in his right knee in the first game last season and missed the remainder of the season.

Hyndman, a 25-year-old central midfielder, has started in all seven games this season and played all but a possible nine minutes. He has 42 appearances, including 33 starts, with the team. He has four goals and six assists in his career in MLS regular-season games.

Hyndman typically is a calm presence on the ball and a good outlet for a pass when Atlanta United recovers the ball in its half of the field. He has completed 89.5 percent of his passes this season, putting him in the top 90 percent of all MLS players this season. On defense, he ranks among the league’s better players at intercepting (82nd percent within MLS) or blocking passes (81st percent).

Manager Gabriel Heinze has a few options to replace Hyndman. He could drop Marcelino Moreno back from his attacking midfielder role into the central midfielder role. He also could use Franco Ibarra or Matheus Rossetto. Mo Adams, who has yet to play this season because of an injury sustained in the offseason, also is a possibility if he is healthy.

Rossetto joins a list of players who have missed games this season that includes midfielder Ezequiel Barco, centerback Alan Franco, Adams, goalkeeper Alcec Kann and winger Machop Chol.