There have been plenty of surprises in the 2011 NBA Playoffs.

First there was the first-round defeat of number-one Western Conference-seed San Antonio to eight-seed Memphis.

Then there was the 2009 Eastern Conference Champions Orlando losing to perennial underachievers Atlanta in the first round.

Back in the West, the Dallas Mavericks not only beat the back-to-back Champion Lakers, but swept them, and in rather convincing fashion. Meanwhile, Memphis is giving favorites Oklahoma City a competitive series, and Atlanta has been playing strong basketball against Chicago.

A Miami Heat victory over the Boston Celtics wouldn't be a huge surprise since the Celtics didn't match up well with the Heat, particularly with Rajon Rondo being hindered by injuries.

But a comeback by the Celtics, who are down three-games-to-one in the series, would certainly be a surprise. It's very rare for a team to battle back from a 3-1 series deficit, and the Heat have a lot riding on this season.

The Celtics have been rather inconsistent in the postseason. In the first round, the Knicks were competitive in both games in Boston, but the Celtics were able to pull off a sweep, which wasn't expected since many experts predicted that New York would at least win one game in the series.

Would a three-game winning streak by the Celtics be viewed more as an epic triumph for Boston, or as a pitiful collapse by the Heat?

The Heat, who have been scrutinized all season, would probably bear more of the media attention should they lose the series. The Celtics, who have been to the Finals two of the last three years, would likely not receive too much criticism for falling to Miami.

However, discussions would swirl about the wisdom of the Kendrick Perkins trade. Also, there would be talk about how much longer stars Kevin Garnett, Paul Pierce and Ray Allen can continue.

This will likely be Doc Rivers's last season. With the head coach calling it quits, does that mean major changes will be in store for the Celtics? Will general manager Danny Ainge rebuild the roster, and trade veterans for young players?

Of course, Boston can avoid such talk if they battle back against Miami, and the Celtics have the talent and experience to make a valiant effort.

Garnett has already proved that he is capable of having a big night, as he did in Game Three when he scored 28 points, and pulled down 17 rebounds.

Pierce has had back-to-back games where he's scored 27 points. Ray Allen went nine-for-13 from the field in Game Two, and scored a total of 25 points.

But the Celtics' Big Three have had their share of struggles against Miami, as well. It will take all three to have strong games - or at least two out of three - the rest of the way if they expect to mount a momentous turnaround.

As for Rondo, the Celtics' point guard played 38 minutes in Game Five, and though his elbow is probably still bothering him, he will likely still plenty of minutes.

Rondo's comeback story after dislocating his elbow could serve as a microcosm for the comeback that Boston could stage.

Perhaps three-straight victories over the Heat will be more of a defining moment for the Celtics than their 2007-2008 NBA title. As Garnett, Pierce, and Allen have gotten older, many have questioned whether they can keep winning.

Not only would they silence those critics, but the veteran All-Stars can prove to everyone that they had the heart to come back against an elite team.

It will take a lot to hold off Miami. Dwyane Wade has had a strong series, and LeBron James has been his usual dominant self. Meanwhile, Chris Bosh bounced back from a lackluster Game Four performance with a 20-point contribution in Game Five.

In other words, it will be a very difficult task to beat the Heat the way they are playing.

But in a playoffs of surprises, the improbable has a way of happening.