BOSTON (AP) — Celtics coach Joe Mazzulla said he didn't walk off the court feeling any panic following Boston's 119-115 Eastern Conference semifinals loss to the 76ers in Game 1.

If anything, he thinks his team saw on tape a blueprint of exactly what they need to do to rebound in Game 2 on Wednesday.

"I don't think it was a letdown, we just lost the game," Mazzulla said. "Hindsight is 20-20, you always have the answer after."

What he and his staff observed was a Boston team that made lots of little mistakes in the second half. That, along with a 45-point performance by James Harden and 17 3-pointers by the 76ers, was too much for Boston to overcome.

"There's pockets of that game that we can handle better," Mazzulla said. "Then obviously late-game execution can get better. Switching, and different coverages and just finding floor space. So, I think it's just honing in on what we're great at and working to do it. … And then clean up some areas where we can be a little more physical."

Celtics guard Derrick White said they can and will adjust. It starts with Harden.

"We've got to make it a little more difficult for him," White said.

What's troubling for the Celtics, though, is that Philadelphia was able to win the physical battle down the stretch without All-Star Joel Embiid, who was sidelined with a sprained right knee.

Embiid went through some light work on the court for the second straight day Tuesday, but he was listed as doubtful on the 76ers' initial injury report.

The plan was for him to do some running on his injured knee and see how it responds.

"The fact that he's doing that is a step forward for sure," coach Doc Rivers said. "It's just health-based. If he can play, he can play. If he can't, he can't. If it's 50-50, we would probably err on the other side (and not play him) because that's what we've done all year. We're not going to take any chances with him."

76ERS AT CELTICS

76ers lead 1-0. Game 2, 8 p.m. EDT Wednesday, TNT

— NEED TO KNOW: With Joel Embiid out with a sprained right knee, James Harden picked up the slack to the tune of a 45-point performance that matched his career playoff high. Boston led by as many as 12 points in Game 1 after a fast start, but had several key mistakes down the stretch, including a late turnover to help Philadelphia seal the win.

— KEEP AN EYE ON: Celtics C Al Horford. Philadelphia targeted him on offense, using pick-and-roll sets to get Boston to switch him onto Harden. Harden used his speed to create space on the perimeter and made several 3-pointers with the big man defending him. The Celtics will have to adjust.

— INJURY WATCH: Embiid went through another workout with the 76ers training staff. The team is waiting to see how his sprained knee responds before making a decision for Game 2.

— PRESSURE IS ON: Boston. The Celtics failed to take advantage with Embiid out. Falling behind 2-0 in the series would put the 76ers in the driver's seat with the series shifting to Philadelphia for Game 4.