After opening the season with two victories in three games, the 49ers have looked awful in losing back-to-back games to New Orleans and New England. Now, they face an important game against the Philadelphia Eagles.

Things have gotten to the point in which there are whispers around the team that if the 49ers are unable to gain a victory before the bye week - the 49ers have games against the Eagles, New York Giants and Seattle Seahawks - that coach Mike Nolan could be out of a job at the bye week.

"I think as of the last two weeks, I've been disappointed in our performance," Nolan said. "Up to that point, as I said even after the 0-1 start, that I felt we were a better team than the year before at 1-0. So at 2-1, I felt pretty good about that."

But in consecutive losses, the 49ers' defense performed poorly. The 49ers own the most experienced secondary in the NFL, yet they gave up big plays with their veterans committing rookie-type mistakes. While the defense was scuffling, the 49ers' offense also failed to get the job done. Quarterback J.T. O'Sullivan threw five interceptions in the past two games.

Nolan has recorded an 18-35 record since taking over as head coach in 2005. He had two days of meetings with 49ers ownership at the conclusion of last season before it was decided he would return for a fourth season. Nolan had power of personnel decisions his first three seasons. When the organization decided he would return this season, the club promoted director of player personnel Scot McCloughan to general manager.

Regardless of the impact that the next three games might have on his future with the 49ers, Nolan said he is not approaching it any different than normal.

"I'm always, every day, doing that," Nolan said. "I was doing that last year. Nobody asked me that question last year in the season. But that's what you're doing. You're doing that at all times. This week, I'll be doing that again.

"If you're 5-0, you're coaching for your job. So that doesn't change. That's just the nature of the beast."

The 49ers have shown some reasons for optimism this season. The offense is far better than it was a year ago, when they ranked 32nd in the NFL. The defense was expected to be much better than a year ago, but it is tied for 21st in the league.

The 49ers have averaged 5.5 yards per offensive play, while surrendering 5.0 yards per play. However, the opposition has run 66 more offensive plays in five games. The defense can't get off the field on third downs, and the offense still has too many three-and-outs.

"Man, we're going to be fine," 49ers running back Frank Gore said. "We just have to play it one at a time and get over the hump."

Linebacker Patrick Willis said the problems on defense have come because there is not the attention to detail that is required. The opposition has converted on 41.4 percent of third-down conversions.

"Once we get back in that attack mode we'll be all right," he said. "We can still create a lot of plays for ourselves. We have a bunch of playmakers on this defense, and we just have to get back to where we're playing as a unit."

It's a big game for safety Michael Lewis, who will be facing his former team for the first time. But, he said, it's much more important to win a game than to get any revenge.

"All the pieces are in place here," Lewis said. "We just have to continue to come together as one. We're not playing together. We have the team in place and every week we're working toward that goal.

"I don't hold any vendettas or personal beefs with Philadelphia. We need to win."

SERIES HISTORY: 27th regular-season meeting. The 49ers lead 16-9-1, though the Eagles have won three of the past four meetings. The 49ers and Eagles played in 2005 and '06, with the Eagles winning those games by a combined 8-27.