No one said defending the NBA title was going to be easy.

The Boston Celtics didn't say it. The coaches didn't say it. The critics didn't say it either, many of them citing age and complacency as the spoilers of a second title run.

Several teams were mentioned as possible successors. The Philadelphia 76ers and their newly acquired All-Star Elton Brand; the Orlando Magic with a older and wiser Dwight Howard; the Washington Wizards, optimistically awaiting the return of Gilbert Arenas; and the Detroit Pistons, who have advanced to the Eastern Conference Finals in six consecutive seasons.

However, each of these teams is gravely flawed. It remains to be seen if Brand can stay healthy for 82 games. Howard couldn't carry the Magic last season and there are no insurances that he can get it done this year. The Wizards simply can't avoid injuries. And last season's Eastern Conference Finals showed that Chauncey Billups, Rip Hamilton, Tayshaun Prince, Rasheed Wallace, and Antonio McDyess lacked the drive and explosion that won them a championship four years ago. 

The most likely candidate to dethrone the champs seemed to be in the Western Conference, which pointed to another return to the NBA Finals for the Celtics.

That is, until Allen Iverson was traded to the Motor City in a deal for Billups and McDyess. Now, the Celtics have some competition in the East.

In one move the Pistons got rid of two weaknesses that aided the Celtics in their six-game Conference Finals victory. Last season, Billups was hampered by a hamstring injury and played nowhere near the standard he had established during previous playoff runs. This setback gave Celtics point guard Rajon Rondo the advantage in the battle of young vs. old and crippled the Pistons backcourt.

Point guard woes were not the Pistons only downfall. As a starting power forward, McDyess brought a nice midrange jumper to the Pistons' frontcourt but lacked any type of defensive game. His perimeter skill set didn't mesh well with starting center Wallace, either, who also preferred to play on the perimeter.

With McDyess giving up 35 pounds to Kendrick Perkins, the Pistons were most effective when they played Jason Maxiell down low and moved Wallace to the four spot. Now, McDyess no longer stands in Maxiell's way. The Pistons have freed up playing time for him to develop into a stronger post player, while their frontcourt becomes more physical with him and Wallace, who is bound to step up his game in a contract year.

Iverson gives the Pistons one of the top scorers in the league, someone who can be counted on to score 25+ points a night. His ability to break down a defense will give spot-up shooters like Hamilton and Prince more open looks as well as allows the explosive Rodney Stuckey to make his way to the basket.

Much like Kevin Garnett and Ray Allen did last season, Iverson is coming to Detroit hungry to reach an unfulfilled goal. At 33 years old, he knows time is running out to get a ring. Iverson's presence will reinvigorate a group of players who have already won it all and are anxious to do it again.

No one said defending the NBA title was going to be easy for the Celtics and the Pistons are making sure of it with this season-changing move.

Jessica Camerato covers the Celtics for WEEI.com.