The Cleveland Cavaliers roster is certainly one of the favorites for the upcoming NBA season. Even before LeBron makes the official announcement that he is returning home, several bettors have already made bets in favor of the Cavs. 

Cleveland has also sold out tickets for the entire NBA season. How about that. 

However, that was just the beginning. LeBron's return to Cleveland has made the Cavs an immediate title contender and an attractive destination to free agents.

Some players who the Cavs have acquired so far include veterans Shawn Marion, Mike Miller and James Jones, and one of the elite power forward/centers in the league in Kevin Love. 

In spite all of the talent this team has, it may not be enough to win it all at the NBA Finals next season. Here are four reasons why:

1. This team has not played a single game together

Aside from a few players like Kyrie Irving, Anderson Varejao and Dion Waiters, most of the players of this team has not played together. There will certainly be some adjustments, but the question now is whether they'd be able to adapt to their teammates and the coaching staff's gameplan right away.

2. Cavs' roster is average at best when it comes to defense

Right now, the Cavs only have two players who can play elite defense - James and Marion. But most likely, the two players will not play at the same because Marion can easily slip to the small forward position, while the other bigs 'sort of' protect the paint. Defense wins championships, and if the Cavs are not able to play good team defense, then they're going nowhere especially deep in the playoffs. 

3. Superstar players may see a drop in performance

The three superstars in this team were the main guy for their respective teams before joining Cleveland. While James may see the same statistics in his previous years, both Irving and Love, who are playing alongside another superstar for the first time in their careers, may not get the same results. 

4. The San Antonio Spurs is still better

San Antonio may be an aging team, but its core is intact and it has a bunch of guys who can step up when it matters most. With a team that has played for more than three years straight already (not including those THREE that has played with each other for a decaed), and an award-winning coach, the Spurs may not win in a sprint against the Cavs, but certainly has the advantage in a marathon which is the NBA season and playoffs.