Barring a dramatic change of course, the San Francisco 49ers plan to fire head coach Mike Nolan after the team's game against Seattle on Sunday, a source told ESPN's Michael Smith on Monday.

Next week is the 49ers' bye week. Nolan is expected to be replaced by assistant head coach Mike Singletary. When reached by ESPN, a 49ers spokesman said: "We don't respond to speculation. We are focused on Seattle."

Nolan, 49, is in his fourth season with the Niners, posting an 18-37 record. San Francisco is 2-5 this season and has lost four in a row. The 49ers are 23rd in both offense and defense in the league.

The 49ers have had five straight losing seasons and are 4-12, 7-9 and 5-11 in three full seasons under Nolan, who was retained after last season, which saw Scot McCloughan, their top personnel executive, formally anointed as general manager with a contract extension and a raise.

The 49ers haven't made the playoffs in Mike Nolan's first three seasons. Richard Allan/Icon SMI

Nolan previously had the final say on all football decisions. He and McCloughan have made joint decisions on personnel issues, but McCloughan has had the final say.

"I will remain the one voice in this organization, and the face," Nolan said at the conclusion of the 2007 season. "I don't believe it will change at all. The important thing is that we will maintain the relationship."

Entering this season, Nolan had two years remaining on a five-year, $8 million deal.

Michael Smith covers the NFL for ESPN.