Chelsea's defensive struggles have been a cause for concern as they currently sit at the bottom of the Premier League table with just five points from their first five matches. The Blues' defense has conceded eight goals in those five games, which is more than any other team in the league so far this season.

The reason behind Chelsea's poor defending has been attributed to several factors. One of the main issues is that the team lacks depth in terms of quality defenders. The likes of David Luiz and Andreas Christensen have both struggled with injuries, leaving the backline vulnerable to attacks. Additionally, the absence of key players such as Cesar Azpilicueta and Antonio Rudiger due to international commitments has also contributed to the Blues' problems.

Another factor contributing to Chelsea's defensive woes is the lack of discipline on the pitch. The team has made numerous errors in possession, leading to counter-attacks and conceding cheap goals. This has led to frustration among fans and players alike, with some questioning whether the team has the mental strength to compete in the top tier of English football.

To address these issues, Chelsea will need to make some significant changes in the transfer market. They should look to bring in experienced defenders who can provide stability and leadership to the team. Some potential targets include Sergio Ramos, Toby Alderweireld, or even former Blues defender Gary Cahill.

In addition to strengthening the defense, Chelsea will also need to focus on improving their midfield and attack. The team's lack of creativity in the final third has been a major problem, and finding solutions to这个问题的答案是需要加强中场和攻击线。在中场方面，球队可以考虑引进像托莫里、特拉奥雷这样的年轻球员来提升他们的技术和创造力。而在进攻线上，切尔西应该寻找一位能够提供威胁的前锋，例如卢卡库、萨乌尔或者维尔纳。

总之，切尔西的防守问题是一个严重的问题，他们必须采取措施解决这些问题。通过加强防守和改进中场和进攻，切尔西有望提高他们的表现，并最终重返顶级联赛的竞争行列。