Pierce, who missed much of training camp and the team's first three games due to a bruised right heel, will make his season debut in the team's home-opener at TD Garden. Rivers stressed the decision wasn't based on an 0-3 start.
"We could be 3-0, I would be playing Paul tonight; We could be 0-3 and we would play Paul tonight," said Rivers.
But that doesn't necessarily mean Pierce is 100 percent, just good enough to gain medical clearance to play.
"I don’t know what percentage he is, honestly. I just know [team trainer] Eddie Lacerte said Paul should play tonight, so I’m going to play him tonight," said Rivers. "We’ll probably find that out after the game; I’ll tell you what percentage I thought he was. But really, I don’t know. I just know it’s good to have him on the floor. He has great ability, we know that. Whether we can get it out of him today or not, we don’t know, that’s part of the lockout season. You don’t have practices to get guys back in shape and ready, you have to use games."
Maybe Ray Allen said it best: "Well, when you're down three, you want to get your team going, you want to get everybody on the same page. But, we're still young in the season and having Paul healthy is the ultimate key. So, I'm glad to have him back."
A couple more injury notes from pregame:
Chris Forsberg/ESPN Boston
Newly acquired Celtics swingman Mickael Pietrus on the floor at the TD Garden.* Celtics forward Chris Wilcox will sit out Friday's game with a bruised left shoulder. The offseason addition said he's feeling better and expects to play Sunday in Washington.
"I'll probably be ready to go next game -- Sunday, I'll be ready to go," he said. "I'm going to get a practice in [Saturday] and then see how I feel, go from there."
Wilcox said he thought he got tangled up chasing a rebound in the Miami game, leading to the bruise. He sat out Wednesday's road trip finale in New Orleans. But he stressed that the injury is healing and he didn't undergo any further tests.
"No, I didn't get any more tests on it," said Wilcox. "Hopefully everything healed up right. I'm going to just take a chance with it and see what's going on.... "It's definitely important [to not rush back]. That's why I wanted to play tonight and they were just like, 'Nah, not tonight. You need to heal up.' So that's what I'm going to do."
* Recently acquired Mickael Pietrus spent time on the floor with his new teammates before Friday's game. He said he needs two more weeks to strengthen the knee after surgery in July, but said he's completely healthy. He then knocked on the Garden parquet hoping to prevent jinxing himself.