WALTHAM, Mass. -- Boston Celtics coach Doc Rivers loves his team's mental toughness. It's been on display throughout a hurdle-filled 2011-12 season. Sure, he'd love his team to take the easier route sometimes; he's just not sure that's possible.
"I keep saying with our team, we don't ever do it the easy way. But I don't know if we could," Rivers admitted. "Sometimes I just don't. Not because the mental [aspect], just because we are bent, and there are times that we do break, and more for other reasons than basketball."
The latest example of upping the season's degree of difficulty: The Celtics kicked away an 18-point second-half lead during Game 4 of their Eastern Conference semifinal series with the Philadelphia 76ers on Friday night. That tied the series at 2 as it shifts back to Boston for Game 5 on Monday night at TD Garden.
Rivers chastised the Celtics after they "completely lost our discipline," particularly on the defensive end late in Friday's loss. But Rivers also knows that adversity has a way of bringing out the best in his team and thinks it will respond well in what's now a best-of-three series.
"I think they're upset, they clearly understand what happened," Rivers said. "But you also understand that just happens. It's happened every night [in the playoffs]. If you watched both games [Saturday] night, you're like, 'Wow.' It just happens, and you move on."
The Celtics spent a lot of time Sunday answering questions about Game 4, but captain Paul Pierce may have said it best in terms of putting the game behind them.
"It's over. Milk is spilled, got to clean up, move on to the next game," he said. "You can't let it frustrate you, can't dwell on the past. It is what it is. The series is 2-2, obviously we have to go back to Philly. But we've got to take care of business at home."
Kevin Garnett also acknowledged the importance of Game 5. "It's critical," he said. "Nothing more, nothing less than that. We're at home, we've got to win."
Pierce said the extra day off between Games 4 and 5 probably worked against Boston this time. It's only the second time this postseason that the Celtics have received an extra day of rest in a tightly packed schedule, but the players are eager to get back on the court and atone for the lackluster second-half effort in Game 4.
Pierce pointed to the "little things" to clean up, like doing a better job on the glass (Philadelphia outrebounded Boston 52-38), limiting second-chance opportunities (the 76ers had 17 offensive rebounds and 12 second-chance points) and winning the 50/50 game (Philadelphia outhustled and outmuscled the Celtics throughout the second half).
One chess match to watch is how the Celtics counter when the 76ers go small, often using Thaddeus Young at the 4 and rookie Lavoy Allen at the 5. Boston typically has gone small to counter the move, taking Brandon Bass off the floor and running four guards with Garnett. But that backfired Friday.
Rivers said the Celtics have to be careful about making knee-jerk reactions to one bad half.
"Honestly, if we made one mistake, we should have gone back to Bass," Rivers said. "In the first three games, our small lineup was a better lineup than our big lineup. Statistically, in Game 4, the big lineup was better; the big lineup was what got us the lead. The big lineup at the beginning of the third got off to a good start. And both times when we went small, it hurt us.
"So that's something as a staff we have to recognize, and it's a tough call. We're going to have to make a call each game, it looks like, and there's no right or wrong to it. It's going to have to be a gut feeling and I hope when we make it, we make the right one."
The Celtics haven't had to make too many tough personnel calls this postseason because they've been able to keep their players upright. But Rivers held second-year shooting guard Avery Bradley out of practice Sunday after his left shoulder was dislocated for the third time this postseason on Friday. Bradley toughed out the rest of the game -- and is expected to start Game 5 -- but his shoulder is a perfect example of the tenuous nature of the Celtics' season.
"That's the scariest part about our team," Rivers said. "I've said it for about three months, we are very thin. That's why games like the other night hurt you more. We don't have a big margin for error. We don't even have it when guys are healthy.
"Our [starters] have to play well to give our bench guys a chance to stay on the floor longer, which allows us to get more rest. There's a minute number every game that I'm concerned by for our starters, and when they get over that we struggle.
"There's a lot of things going on in a game every night for us that quite honestly a lot of teams don't have to deal with. But we know that and we understand that."
Yes, the Celtics know they've been forced to navigate the hard path this season. Through it all, they've emerged at the other end. And as Game 5 approaches, they're confident in their chances to do the same yet again.