BOSTON -- To successfully defend their NBA championship, the Milwaukee Bucks knew they needed a combination of strong player performances, health and, perhaps, a little bit of luck.

But the absence of forward Khris Middleton loomed large throughout their Eastern Conference semifinal series against the Boston Celtics and was ultimately too difficult to overcome as Milwaukee's season ended with a 109-81 loss in Game 7 on Sunday.

The Bucks failed to reach 100 points in three of the seven games (all losses) and were badly outshot from behind the 3-point line. Boston made 53 more 3-pointers than Milwaukee in the series, which according to research by ESPN Stats & Information, is by far the largest gap in a single series in NBA postseason history.

"We could've used [Middleton], definitely could've used him," Bucks guard Jrue Holiday said. "He makes big shots and big plays on both ends, but especially offensively."

Without Middleton, who sprained the MCL in his left knee during Game 2 of their first-round matchup with the Chicago Bulls, Bucks star Giannis Antetokounmpo did his best to carry the team through the series.

Antetokounmpo averaged 33.9 points, 14.7 rebounds and 7.1 assists during the series against a Celtics defense that finished No. 1 in the NBA in efficiency during the regular season. He finished with as many 40-point games in this series (three) as the Celtics surrendered all season. And Antetokounmpo became the first player in league history to score 200 points, grab 100 rebounds and dish out 50 assists during a single series.

"The way Giannis evolved through the series, the way Giannis played against a very good defensive team, against a lot of good individual defenders was like another one of those growth moments and growth plate opportunities," Bucks coach Mike Budenholzer said. "I thought he was phenomenal -- his scoring, his attacking, his playmaking, his unselfishness.

"There's always going to be one or two times where we could've been better, he could've been better, but I would say as the series progressed I was beyond impressed with him and how he kind of figured out how to attack, how to score, how to playmake, how to do all those things. We didn't get it done, and he's a big part of that, but I'm beyond impressed by how he progressed through the series."

Antetokounmpo started off hot Sunday, going 6-for-10 in the first half for 17 points before he appeared to get fatigued while struggling down the stretch. He shot just 4-of-16 in the second half with 8 points as the Celtics pulled away after halftime.

"Legs heavy. Body heavy. Mind heavy. Everything was heavy," Antetokounmpo said with a smile after the game. "I was just trying to be aggressive. At the end of the day, it's Game 7 and I'm not going to hold the ball and not look at the rim. I'd rather miss a bunch of shots and keep playing and keep coming and keep being aggressive. Keep looking for my teammates and keep making the right plays, then go in passive mode. I can live with that."

Antetokounmpo had to take on a large share of the scoring burden for Milwaukee all series, becoming the first player with 25 shot attempts in seven straight playoff games since Allen Iverson in 2001, according to ESPN Stats & Information.

Yet, after the game, Antetokounmpo said he enjoyed competing in this series against Boston despite coming up short because of the effort his team gave each game.

"I don't think I shied away from the physicality of it," Antetokounmpo said. "Any of the games. Through adversity, kept coming. That's who I am, that's how I'm built. ... I enjoyed it. It definitely made me a better player. You get better through experience."

In the end, however, Antetokounmpo couldn't do it all alone and the Bucks had too many empty performances from their role players. George Hill did not score a point in four of the five games he played. Grayson Allen shot 20.8% from 3. The Bucks shot just 27.9% from 3 as a team. Aside from Antetokounmpo and Holiday, Pat Connaughton was the only other Bucks player who averaged double-digit scoring (10.3), although Bobby Portis averaged 9.9 points per game in the series.

"Obviously we weren't trying to make excuses," Antetokounmpo said. "I think everybody went out there to compete and give everything they have. That's what we did from Game 3 against Chicago to Game 7 against Boston. If we had [Middleton], maybe it would've been a different story. But we didn't."