The Portland Timbers say that veteran defender Mikael Silvestre is out for six to nine months because of a left knee injury.
Silvestre tore his anterior cruciate ligament during a scoreless draw against the New England Revolution on Thursday night and was taken from the field by stretcher.
In response, the Timbers signed defender Pa Modou Kah for the rest of the season
The team says the 32-year-old Kah, who has played the past two seasons in Qatar and Saudi Arabia, will join the club once he obtains his visa.
Kah played seven seasons with Dutch side Roda JC. Before that, he helped Norway's Valerenga win a title in 2002. He also has 10 caps with Norway's national team.