PHILADELPHIA -- After James Harden had a second straight dreadful shooting night -- and the Philadelphia 76ers lost a second consecutive game to the Boston Celtics in the Eastern Conference semifinals -- Joel Embiid had a message for his point guard heading into Game 4.

"I mean, you just talk to him and you keep telling him to keep shooting," Embiid said after Boston's 114-102 Game 3 victory. "Be aggressive. Can't get too high, can't get too low. Some nights you're going to make lots of other shots, a lot of tough ones, and some nights you're not going to make them. So it's about finding other ways to impact the game."

Unfortunately, most of Harden's impact on Game 3 was negative for the 76ers. After putting together the single-best playoff game of his career by tying his career high with 45 points in Philadelphia's Game 1 victory, he followed that performance with a 2-for-14 showing in Game 2 on Wednesday night and a 3-for-14 exhibition in Friday night's loss at Wells Fargo Center.

The combined 5-for-28 shooting in those two games is Harden's worst output in that span in his career, per ESPN Stats & Information.

When asked after the game if Boston had done anything to slow him after his Game 1 performance, Harden simply said, "Nope."

Celtics guard Malcolm Brogdon disagreed, saying the Celtics had made an effort to slow Harden, with Jaylen Brown being particularly effective in guarding him.

"We're purposefully making it hard on him," Brogdon said. "He came out in Game 1 and won them that game and played terrific. We don't want him to play like that anymore, so we got to be as physical as we can with him. Force him into tough shots, make him uncomfortable and really learn to compete."

Sixers coach Doc Rivers repeatedly said Philadelphia needs to play with more force. He believed the team had driving lanes to attack but failed to take advantage of them. On several occasions, Harden made forays into the paint, but looked indecisive and passed -- often leading to turnovers.

"I thought there was a couple times we came out of a time out and thought we had the lane," Rivers said. "That's something we talked about, getting into the paint with force, with pace and if they come, let's make plays. Just didn't think we did that."

That was especially true in the first half, when Harden committed five of Philadelphia's 11 turnovers that led to a 57-50 Celtics halftime lead they would never relinquish.

"I got to watch the game," Harden said, when asked about those drives inside, "but I'm pretty good on basketball instincts. I know when to score and I know when to pass.

"So I'm pretty sure a lot of them was the right play."

Harden's second consecutive rough night overshadowed a similar clunker from fellow guard Tyrese Maxey, who finished the game on 4-for-16 shooting, and the two of them combined to go 2-for-14 on 2-point shots. As a team, the 76ers shot just 15-for-41 (36.6%) on 2-point shots on the night. Remove Embiid's shots from that number and it drops to a dismal 7-for-24 (29.2%).

The Celtics had seven blocked shots -- including three by Robert Williams III -- and Embiid said what appeared obvious to the naked eye during the game: That challenging the length of the Celtics repeatedly at the rim wasn't necessarily the best way to approach the game.

"You've just got to obviously be aggressive and still pick his spots," Embiid said about Maxey. "Robert Williams is pretty good defensively, blocking shots, and so you can be reckless driving into him. You can make some, but with how athletic he is, there's a chance he's going to block it or change the shot. I think you just got to stay calm and play at a better pace instead of just attacking and going fast. I think that's really been an issue. But like I said, same thing for [Maxey]. There's no panic. We just got to settle down."

Embiid and Rivers also pointed to Boston winning more 50-50 balls and getting several timely offensive rebounds -- four of them coming in the fourth quarter, when the Celtics held off a few 76ers challenges with timely 3-point shots, including twice when Brogdon and then Horford faked out defenders before draining triples.

Ultimately, Embiid said that it comes down to the 76ers simply playing better beginning Sunday afternoon in Game 4 if they want to stay alive in this series.

"I think players have to show up," said Embiid, who finished with 30 points, 13 rebounds, 3 assists and 4 blocks in 39 minutes and accepted the NBA's MVP award in an emotional pregame ceremony that saw him break down when his son, Arthur, ran to him on the court. "I got to do my job. All the guys, everybody knows their role, they have to do their job. Players have to show up. Obviously, you can make any adjustments you want. But if the players don't execute, they don't show up and we don't make shots, that's on us.

"I got to be better. We all got to be better. We just haven't been good enough the last two games. No sense of urgency ... it's the small things. We've been fine guarding them in the half court. It's loose ball situations, offensive rebounds, and they knock down a 3 or they score off of it and it just changes everything."