A statement from the SvFF said the decision had been taken after it emerged that an AIK player had been offered money to underperform in fixture.
Olsson, 34, would have been out of contract in the summer, but has reached a mutual agreement with Albion to terminate remaining months of his deal.
Asked whether he had other options with another U.S. club, Diskerud said only: "Yes and no."
U.S. international Mix Diskerud has sealed a loan to Swedish side IFK Goteborg following his tumultuous exit from New York City FC.
U.S. international Mix Diskerud is close to securing a loan to Swedish side IFK Goteborg, an MLS source told ESPN FC.
Isak became the youngest player to ever score for Sweden when he struck in the 6-0 win against Slovakia on Jan. 12.