DAVIE, Fla. -- Miami Dolphins coach Dave Wannstedt called it quits Tuesday midway through a dismal season that began with the retirement of running back Ricky Williams and has left the team with the NFL's worst record at 1-8.

Defensive coordinator Jim Bates was promoted to interim coach.

"As you might imagine, this was not a very easy decision from a personal standpoint, but I believe it is a proper decision at this time for being a professional," Wannstedt said. "Somebody has to accept the responsibility. I am the head coach and that falls on me."

Wannstedt's resignation came after he met Monday night at the team complex with owner Wayne Huizenga. The timing of the coaching change wasn't surprising, with the Dolphins beginning their bye week.

Dolphins president Eddie Jones said he and Huizenga tried to talk Wannstedt out of quitting, but the coach made the case that his departure would be best for the team.

Bates' first game as interim coach will be Nov. 21 at Seattle. He was head coach of the USFL's San Antonio Gunslingers in 1985 and joined the Dolphins as defensive coordinator when Wannstedt became head coach in 2000.

Bates said that while some starters might be benched, major changes are impossible at this point of a season.

"We can't change the offense, we can't change the defense," Bates said.

Wannstedt's final defeat came Sunday, when Miami blew two leads and lost 24-23 to the Arizona Cardinals, who ended a 17-game road losing streak. The Dolphins endured their most lopsided defeat of the season last Monday, 41-14 against the archrival New York Jets.

Dolphins players were aware of Wannstedt's tenuous situation and rising discontent among fans.

"I feel sorry for the guy because he's a first-class guy," cornerback Patrick Surtain said after Sunday's defeat.

"It's not like guys aren't going out there giving 110 percent and laying it on the line for him. We're doing it all -- getting holding penalties, offsides, we're doing crazy stuff. How can he control that when he's on the sidelines?"

Wannstedt barely avoided being fired after last season, when Miami failed to reach the playoffs for the second year in a row. Huizenga decided to keep Wannstedt, but stripped him of authority over personnel decisions.

Little has gone right for Miami since. Wannstedt was twice forced to change offensive coordinators during the offseason, and Williams abruptly retired just before training camp. Receiver David Boston, the top offseason acquisition, suffered a season-ending knee injury before the first exhibition game.

That was the start of an injury wave, and the Dolphins have had the worst start in their 39-year history. They're one defeat from their first losing season since 1988.

Wannstedt, who succeeded Jimmy Johnson in 2000, has a record of 43-33 in Miami. His career NFL record, including six seasons with the Chicago Bears, is 84-90.

Wannstedt was fired in 1997 by the Bears. His final two teams there went 4-12.

The Dolphins won only one playoff game under Wannstedt, and that was four years ago. Even with seven Pro Bowl players in 2002, including NFL rushing champion Williams and sacks leader Jason Taylor, the Dolphins missed the playoffs.

One of Wannstedt's first moves when he became coach was to nudge a 38-year-old Dan Marino into retirement. As a replacement Wannstedt acquired Jay Fiedler, who has never been popular with Dolphins fans.

Wannstedt was just the fourth coach in Dolphins history, and only Don Shula coached the team longer.

While the Dolphins have been a perennial playoff contender -- until this year, at least -- they haven't reached the AFC championship game since 1992. Their last Super Bowl berth was in 1984, and they haven't won an NFL title since 1973.

Huizenga, who became sole owner of the Dolphins in 1994, has been through three coaches in pursuit of a championship. He nudged Shula into retirement following the 1995 season, and Johnson called it quits four years later.

Speculation regarding the next coach began weeks ago, with LSU's Nick Saban, Philadelphia Eagles offensive coordinator Brad Childress and New England Patriots offensive coordinator Charlie Weis mentioned as possibilities.