John McLaren has been fired as manager of the Mariners, the Seattle Times reported on its Web site Thursday.
Bench coach Jim Riggleman has been promoted to the position, according to the report.
A press conference is scheduled for 2:30 p.m. ET.
The Mariners are an MLB-worst 25-47 and sit 17.5 games behind the first place Anaheim Angels in the AL West.