The Boston Celtics will be facing one of their toughest challenges this season when they go up against Giannis Antetokounmpo and the Milwaukee Bucks— owners of the league's best regular season record — in the Eastern Conference semi-finals.

Led by the MVP frontrunner, the Bucks turned from a playoff contender to a championship caliber team in only a span of a year. The Greek Freak is one of the most unstoppable players in the league, and the Celtics will surely have their hands full in guarding him.

Celtics general manager Danny Ainge knows what his team is up against. In fact, he told Steve Bulpett of the Boston Herald that Antetokounmpo reminds him of one of the team's toughest adversaries in the past — LeBron James.

“He’s a lot like LeBron in some ways, in that he’s just a good all-around player. Shooting may be his biggest weakness, but it doesn’t really matter if he even makes shots; he’s just so effective at still scoring and scoring efficiently and creating offense. And obviously LeBron’s become a very good shooter as his career has moved on, and Giannis is getting better, too. But the fact is that they’re just bigger and more athletic than most everybody they go against, and they have such versatility offensively and defensively.”

Throughout his 16-year career, LeBron has faced the Celtics six times in the playoffs, eliminating them on four different occasions. But now that he's no longer in the East, another phenomenal athlete has taken his place.

That's Antetokounmpo.

Giannis and the Bucks might become the Celtics' next rivals moving forward, but that hasn't stopped Ainge from admiring the 24-year-old Greek All-Star.

“One thing I really appreciate about Giannis as a player is his enthusiasm and passion for the game. I think it’s a very underrated characteristic, and I think that he is an inspirational player to his team. His teammates, they really appear to love playing with Giannis.”

The Bucks-Celtics series will begin Sunday night at Milwaukee.