WALTHAM, Mass. -- When Celtics coach Doc Rivers settled into his office Thursday morning to map out a plan for the day's practice session, the Miami Heat were on the floor in China for an exhibition game. Rivers didn't exactly go out of his way to turn the TV off.

"I was doing our stuff, but it was on and I kept glancing up," admitted Rivers. "I didn’t really watch it, but it was on in my office while they were playing. We watched -- right now we’re watching the Knicks, too, and we’re watching everybody, because we have to do our prep work for the season and you do it through preseason games. Teams don’t tend to play their [stars] a lot, but they do run their new actions a lot, so we can learn a lot about what they’re trying to do."

Is Rivers used to the look of old friend Ray Allen in his new No. 34 jersey?

"He looked like Ray Allen, just like him," quipped Rivers. "It is [weird]. He wasn’t here for 20 years, but it is still strange seeing him with someone else."

Asked if the Heat are never too far from the Celtics' mind, Rivers said: "They shouldn’t be. But then, a lot of teams shouldn’t be -- Philly, Atlanta, you can go down the list. There’s a lot of good teams in the East and we’re going to have to get through them all to be where we want to go. But the best team in the NBA is Miami, so I think the East and the West, they should be on everyone’s mind."

Rivers has made it a point to stress that training camp is all a process for having his troops ready for when the season officially tips off. The Celtics visit the Heat on Oct. 30 to open the 2012-13 season.