Ray Allen turned 33 this past summer.

That doesn’t mean he’s done. It just means that the Ray Allen of old, the guy who was basically money from anywhere beyond the three-point arc, may not turn up with the same level of frequency these days.

Allen was basically invisible in the season-opening win against Cleveland earlier in the week. He made just two shots, including one trifecta, and finished with just eight points. Maybe it’s just that LeBron and the Cavs have his number of late, since he was abysmal in the playoffs series against Cleveland last season.

But I’m fairly certain we’re going to see a more erratic Ray Allen this season.

Sort of like the one we saw struggle to find his perimeter shot through much of the postseason a year ago.

Allen has been the man everyone he’s been in his entire career. Back at UConn, then through his first seven seasons in the NBA with Milwaukee and even in relative obscurity through five years out in Seattle.

Now he’s a piece.

Let’s be honest. It’s no longer The Big Three on most nights.

And if it is, the third wheel has become Rajon Rondo.

Allen, who is averaging more than 21 points in his career, averaged 12.7 points last April, picked it up against the Atlanta Hawks in the seven-game series before appearing to lose confidence in his perimeter shot against the Cavs. He continued to struggle against Detroit in the Eastern Conference finals before coming up huge against the Lakers.

Whether you want to hear it or not, it’s going to be hit or miss for the veteran scorer.

This is Kevin Garnett and Paul Pierce’s team.

Allen hasn’t complained at all about being the clear-cut No. 3 guy and that’s part of the reason why this team hung banner No. 17 earlier this week. He’s a consummate professional and just goes about his business.

But it can’t be easy for a guy who has scored more than 18,000 points in the league.

It’s almost as if Allen doesn’t know where to get his shots any more. In the old days, he’d be run off several screens and would be automatic from long distance. Now he’s become almost an afterthought in the Celtics offense.

He won’t be the only erratic Allen who needs to come to grips with his role, either.

For the Boston Celtics to hang another banner, athletic wing Tony Allen will have to buy into the fact that he’s a defensive stopper. Boston will score enough points to win games, but defense was what ultimately won the C’s a championship last season.

With James Posey gone, Tony Allen becomes the de facto lock-down wing defender coming off the bench. For a game here or there, it’s fine to put Pierce on LeBron or Kobe Bryant for 40-plus minutes. However, in a seven-game series, Tony Allen will be counted on to give Pierce a rest and guard guys like LeBron and Kobe for a stretch.

Sure, there are times when Tony Allen will explode and provide an offensive spark for the Celtics. He did it in the third quarter on Tuesday night against the Cavs. But then he’ll get carried away and become just as frustrating to watch as Sam Cassell was down the stretch last year when he was jacking ill-advised shots that eventually sent him to the bench.

You know what you are going to get from Pierce and Garnett on most nights.

But for the two guys with Allen written on the back of their shirt, it might be a little bit like going out on Halloween.

Trick or treat?

Jeff Goodman is a senior basketball writer for FOXSports.com.