BOSTON -- Philadelphia 76ers coach Doc Rivers said he was "disappointed" that the NBA's officiating game report from Game 6 of the Eastern Conference finals saw 13 officiating errors disadvantaging the 76ers compared with four for the Boston Celtics, according to ESPN's Adrian Wojnarowski.

"It was disappointing to see, honestly," Rivers said before Sunday afternoon's Game 7 at TD Garden. "A 13-4 disparity ... in a one-point, two-point game, it's hard to recover from. It really is.

"I mean, when you saw the report, which we read and then saw the calls that were missed. The trip on James Harden down the stretch when he fell to the floor, the loose ball where they called a timeout, and they didn't have the ball. Plus, there was a foul on Smart on the play. That would've been free throws. That's hard to recover from. It really is. Having said that, it's a human game, and you have to just try to play through it. Usually, the disparities are never that great. Most games they're two and three, and you can live with those, but 13 and four, that's hard."

Philadelphia had a two-point lead with just under six minutes to go in Game 6 -- after winning Games 4 and 5 to take a 3-2 lead in the series -- before Boston ripped off a 14-3 run to close the game, delivering a series-tying victory.

After Game 6, Harden said he was frustrated by a number of missed calls throughout the night.

"Tonight, it was just frustrating because I'm No. 1 as far as fouls that don't get called," Harden said after going 4-for-16 from the field, including 0-for-6 from 3-point range. "Like, it's a fact. So, it's frustrating as a player when the officials tell you at halftime that 'hey, we missed a couple fouls.' That right there, there was some missed shots and fouls, which is getting me in rhythm, to transition points [for the Celtics]."

As Philadelphia looks to make it to the Eastern finals for the first time since 2001 -- and Rivers seeks his first conference finals appearance since 2012 -- Rivers said everyone feels pressure in these situations, but it's a "privilege" to be part of them.

"Oh yeah, everyone does," Rivers said. "I'd hate to be Billie Jean King, but it is a privilege. It's an honor to keep getting teams to these places. It really is. I mean, it's funny, there's people, your friends who look at you and say, 'Why do like this?' And this is what it's about. You put yourself out there because you want to win, and you know if you do that you have to put yourself in these situations over and over and over again. And it's worth it. It's worth it. It's worth it. And that's what I tell my guys."