The Chicago Fire will be without defender-midfielder Matt Polster for seven weeks because of a left knee strain, the club announced Monday.
Polster suffered the Grade II strain during Thursday's training session in Fort Myers, Florida. The 23-year-old will return to Chicago on Wednesday to continue treatment.
An option at defensive midfield and right back, Polster found himself in a battle for playing time this preseason following the recent additions of midfielders Dax McCarty and Juninho. The defender-midfielder has made 57 appearances (51 starts) over two MLS campaigns.
The Fire open the 2017 season with a trip to face the Columbus Crew on March 4, with Polster poised to return in late March.