After superstars Paul Pierce and LeBron James both fouled out during overtime of Sunday's Game 4 of the Eastern Conference finals, the officiating -- already in the spotlight at times this series -- got thrust to the forefront again.

But Celtics coach Doc Rivers, who has vented at times this series about technical fouls and calls against his team, did his best to be diplomatic when asked about the officiating during a conference call on Monday, stressing that officials have a very difficult job, particularly with the two teams on the floor at this stage of the postseason.

"I think it’s a hard game," Rivers said. "I said that after Game 1 and Game 2, and Game 3 and Game 4. It’s a physical series. We are physical; Miami is athletic and physical. Honestly, I thought the calls down the stretch of (Game 4), they could have gone either way -- there could have been no calls, could have went one way -- just watching it on tape, I just thought those are tough calls. The team that gets one, the other team doesn't like it. That’s just the way it is. Listen, I complain as much as anybody, but, overall, I do understand it’s a brutal job. It’s a brutal job to referee this series."

Rajon Rondo raised some eyebrows with some ref-related comments during a halftime interview on ESPN. When asked what holes he was exploiting in the Heat defense as part of Boston's offensive outburst, Rondo answered, "Them complaining and crying to the referees in transition."

After the game, Rondo didn't retreat, noting, "What I said was true. I don't take back what I said. That's what it is."

Asked about Rondo's comments and whether the Celtics see the Heat complaining to officials when they watch film, Rivers tiptoed around the subject on Monday.

“We watch a lot of film, I’ll just stop there," he said. "Other than that, I don't make comments on that. I mean, Rondo is very emotional, we like him to be intense. Obviously, if that motivates anybody else, that motivates anybody else. But if you need motivation at this point, there's something wrong anyway. As far as what he said, I’ll leave that alone. I’ll just leave it there.”

In Miami, Heat coach Erik Spoelstra downplayed Rondo's comments, calling it "normal playoff chatter."

Asked if there was any validity to what Rondo said, Spoelstra added, "I could really care less -- couldn't care less about what another player has to say about our team. The deeper you get into a competitive series, the more people (say), the more noise there tends to be."

Asked how his team had managed when they didn't get calls, Spoelstra tried to focus on the improvement from past seasons.

"I think we've managed that part of the game better than we have in the past," Spoelstra said. "I think, particularly in this playoff run, we've been able to focus on things that we can control. And that's not one of them. But if you have been around our team, I think you've seen a lot of progress, particularly from last year."