Step into the size 15 shoes of one Mr. Walter Ray Allen for a moment and try to imagine what it's going to feel like at 7:30 p.m. Tuesday.

That's when the Heat's pregame banner-raising and ring ceremonies begin before the season opener against the Boston Celtics at AmericanAirlines Arena. That's when Allen will watch, along with his former Celtics teammates, as 12 of the Heat's players from last season are honored at midcourt for winning the 2012 NBA championship.

The Heat survived Allen's Celtics in an epic seven-game series for the Eastern Conference championship before running through the Oklahoma City Thunder in The Finals.

For about half an hour before the start of the 2012-13 season, Allen will feel more like a member of his former team than he will one of the new additions of the Heat. Then, just like that, Allen will have to flip a switch in his head and go head-to-head against his former mates.

No, this is not just any old season opener – not for Allen, not for the Heat and certainly not for the Celtics.

"I'm happy for them that they won, but at the same time they beat me and put us out, so I understand the emotions that Boston will feel watching the whole ceremony," Allen said. "But at the same time, I'm excited for these guys.

"Once it's over with, it's business as usual."