For the second time in three weeks, the San Francisco 49ers gave up more than 40 points to an opposing team. And for the fifth time in the team's first six games, we got a good glimpse at how bad this defense really is. The 49ers defense has given up more points than any other team in the league. In fact, in their four losses, the team has allowed an average of over 40 points a game.

Fans knew that the defense would be bad going into the season. Those that did not know this were kidding themselves. After all, the front office focused on offense during the offseason, bringing in quality free agents like wide receiver Antonio Bryant and guard Larry Allen. They also drafted heralded college tight end Vernon Davis. The defense on the other hand was not upgraded. In fact, aside from rookie linebacker Manny Lawson, not much was done to replace the defensive players that the team lost.

The defensive backfield is a major concern. Shawntae Spencer is serviceable as a cornerback, but certainly not a premiere player, especially not against the San Diego Chargers on Sunday. Opposite Spencer plays the surprising Walt Harris. While Harris has played well this season, he did not play against the Chargers due to a hamstring injury he sustained near the end of practice on Thursday. However, since the team was outscored by 29 points, it is doubtful that his presence would have made much of a difference. The 49ers were so focused on running back LaDainian Tomlinson, that quarterback Philip Rivers was able to pick apart the defense with ease. And while the defense held Tomlinson to 71 yards, he was still responsible for four of the Chargers' six touchdowns.

Safety Tony Parrish has been a non-factor for most of the season and is not the player he once was. Parrish did not even start against the Chargers. Mark Roman did. Playing alongside him, Mike Adams is another serviceable safety, but not a serious threat for opposing offenses. The 49ers would eventually like to move Marcus Hudson to safety but have been keeping him at cornerback for now.

The team has been trying to sign 5-time Pro Bowl defensive back Troy Vincent who has played with the Buffalo Bills the past two seasons and spent the beginning of this season on the Bills' roster before being released this past Thursday. Since then, the 49ers have been one of a number of teams attempting to sign the 15-year veteran. Vincent has lost a step over the years but would still be a solid safety and may help the teams' dreadful pass defense. He would also provide another veteran leader on the defensive side of the ball.

The defensive line has not been able to get much pressure on opposing quarterbacks. Sunday was no different. While they got close to Rivers a few times during the game, no one was able to bring him down. They got a safety, but that was because Rivers was called for grounding while in the endzone. The line is too small play Nolan's preferred 3-4 defense and they are not doing much better playing the 4-3. They have been trying to find a fit at nose tackle. With no quality free agents available during the offseason, they pressed on with Anthony Adams and Isaac Sopoaga. Combined, these two players would be a perfect fit for the position. Separately, Adams has the quickness and instinct while Sopoaga possesses the raw strength to play the position. Sadly, both player's strengths are the other's weakness.

On offense, the 49ers did well considering they were playing against the NFL's top ranked defense, which was number one against the pass and the run. Quarterback Alex Smith passed for 214 yards, two touchdowns and one interception. However, that interception was not Smith's fault as the pass was batted into the air at the line of scrimmage. Offensive coordinator Norv Turner has done wonders for Smith as most teams now respect his ability to hit his targets and his improved ability to read defenses. On the ground, running back Frank Gore averaged 5.5 yards a carry. Unfortunately, the 49ers were forced to abandon the run after falling behind early.

San Francisco was without Jonas Jennings and has been without Larry Allen on the offensive line. Jennings and Allen are two of the strengths on an improved offensive line. Without them, Smith was flustered by the Chargers' pass rush.

There is not much the 49ers can do to help the defense but they need to do something in order to give this young team any hope of salvaging the season. They can't simply increase the blitzing because they don't have the personnel in the backfield to compensate. Teams would simply adjust and take advantage with short passes and screens. Realistically, the team will have to perform even better on offense in an effort to stay in high scoring games and keep up with opponents. Installing even more trick or misdirection plays could help.

The 49ers fell to 2-4 on the season and are entering their bye week. They will not get much relief once they come out of their bye seeing as how their next opponent is the undefeated Chicago Bears. The Bears are scoring over 31 points per game, which is 1st in the league, and allowing a little over 7...again, 1st in the league. This will be a daunting task for the struggling 49ers who face five teams with winning records during the next six weeks. While the team is improved from last season, they still have a long way to go.