Al Horford, one of the 76ers’ headline free-agent acquisitions, spent the previous three seasons with the Boston Celtics. He was with the Atlanta Hawks the previous nine.

So what does that mean for his first year in Philadelphia?

“I have done this before, so for me, it is a little easier, the transition,” said Horford, a five-time All-Star entering his 13th NBA season. “Another side of it can be overwhelming with all that comes with being on a new team and building relationships, and getting to learn the city and all these things.”

The 33-year-old Horford said the thing that attracted him to the Sixers was their caliber of players, led by Joel Embiid, Ben Simmons, and Tobias Harris. He felt the trio and the Sixers were close to taking the next step toward an NBA title. So competing alongside them and building relationships as teammates excited him. .

“The opportunity to win, I am going in my 13th season, that is important to me,” said Horford, who will get his minutes at center and power forward. “I feel we have an opportunity to win now and that was something that was hard for me to pass.”

The Los Angeles Clippers, the Milwaukee Bucks and Sixers are among the favorites to win the NBA title this season. And Horford and Embiid are regarded as the league’s best post-playing duo.

Embiid was named an All-Star and a second-team All-NBA selection in each of the past two seasons. Sports Illustrated ranks him seventh on its Top 100 NBA Players list regardless of position. Horford isn’t far behind, at 18.

“Being able to have a chance with a guy like Joel is really a dream come true for me,” Horford said. “A guy that can do it all on the floor, I believe he is the best big man in the league right now. To be paired up with him and play off of him and learn how to work with him, I am excited.”

Horford signed a four-year, $97 million contract with the Sixers this summer. He could make up to $109 million.

In Horford, the Sixers got a proven post player to start at power forward alongside Embiid. Horford will also start at center on nights Embiid sits out. His presence could make the Sixers the team to beat in the Eastern Conference.

“It is incredible,” coach Brett Brown said of seeing Horford in a Sixers jersey. “For me, it was incredible. I almost didn’t want to talk about it too much. But if you put me in a room and we are going sort of one-on-one behind closed doors, I am blown away he is here. I am just so excited.”

The coach added that no one can underestimate the relationship between Sixers general manager Elton Brand had with Horford as Hawks teammates. As a result, Brown said Brand deserves a lot of credit for the addition.

“To just have somebody like Al all by himself with his resume and so on coming to our program,” Brown said, “and then you double-down and you are able to get him and the Celtics didn’t -- win, win.​”