Celtics rookie Tacko Fall looks to pass the ball over defender Amile Jefferson during the fourth quarter Friday. John Raoux/Associated press/Associated Press

ORLANDO, Fla. — The chants began raining down from the rafters from Amway Center beginning early in the first quarter Friday, and the chant of “We want Tacko!” came to a crescendo late in the third period with the Celtics leading by 28.

When Celtics coach Brad Stevens walked toward Fall early in the fourth quarter to summon rookie Tremont Waters, he drew boos. The same happened moments later when he called for Vincent Poirier.

Fall was back in Orlando, where he starred for Central Florida and nearly helped the Knights nip Duke in the second round of the NCAA Tournament last spring. The 7-foot-5-inch Celtics rookie had plenty of fans rooting for just a few minutes of action, just a glimpse of the lovable big man.

At the 5:33 mark, Marcus Smart looked to the fans feet away from the Celtics bench and said, “You want Tacko, right?” and advised them to stand up, and Fall approached the scorer’s table.

Fall delighted the fans with a pair of rebounds and an assist in the Celtics’ 100-75 win.

It’s becoming a nightly occurrence. Fall is becoming one of the most popular training camp invitees in NBA history. He is vying for the Celtics’ final roster spot, but he is becoming a household name, a delightful character because of his height and humility.

So what should the Celtics do? They have one roster spot and their two two-way contracts are currently filled. Javonte Green, a rookie free agent from Radford, has impressed the Celtics so much that he is the favorite for the final roster spot.

Tremont Waters, the second-round pick from LSU, and DePaul shooter Max Strus have signed two-way deals. There honestly has to be a method to get Fall onto the roster for several reasons, but his popularity, desire to improve and potential upside are the primary factors.

Let’s be real, the Celtics are here to win games and make money. It’s just that simple. Fall’s presence has to have a positive financial impact on the franchise. The NBA will sell more Fall No. 99 jerseys than Strus’s 28 or probably most other players on their roster.

Of course, the Celtics had no idea Tacko-mania was going to occur when they committed to a two-way deal with Strus or when they signed Fall to an Exhibit 10 contract. Fall went undrafted. He made a splash in that Duke game, but the organization couldn’t have had any idea he would be such a favorite, beginning at summer league in Las Vegas.

And don’t think other NBA teams aren’t watching closely. Couldn’t you imagine a team such as Charlotte, Memphis, or Phoenix signing Fall to an NBA contract, turning him into a development project, and then reaping all of the financial benefits?

If the race to a roster spot – either the 15-man or two-way – is close, then why not sign Fall?

Waters has shown to be a rising prospect, one that could eventually earn a full-time NBA deal. The Celtics want to hold on to him. The question is whether the club wants to keep Green and/or Strus.

Green is a high flyer with an upside as a defensive ace and tenacious scorer. Strus is a long-range shooter who wowed the Celtics with his predraft workout.

It’s not an easy decision and Fall’s popularity as well as his ability to actually give quality minutes in his two preseason appearances has made it tougher. He is never going to be a 38-minute-per-game player but he can become a deterrent for players driving into the paint and big men looking to post.

Fall does serve a purpose on the floor. He is far more than just a fan attraction.

“He just handles everything with a smile,” Celtics coach Brad Stevens said. “He’s an extremely hard worker. He’s very humble. He’s very gracious. He’ll take a picture with everybody who wants to take a picture with him. I hope people appreciate him for who he is and how hard he’s working to try to make the NBA.”

Of course, Stevens is not going to hint to the Celtics potential decision. And there’s two preseason games and the rest of camp — another 10 days — to determine the roster. The Celtics realize waiving him and just trying to sneak him onto the G-League Maine roster likely won’t work.

It was Fall’s responsibility to make the decision difficult and he has. He played 5 minutes, 33 seconds Friday and the Magic actually sent double teams at him on nearly every possession. In today’s free-wheeling, 3-point shooting NBA, where centers have to stretch the floor to defend, it would be difficult for Fall to play against certain teams and in certain situations, but the game hasn’t passed him by.

Fall can serve a purpose for the Celtics. What’s more, he can serve many purposes for the Celtics. It was no accident that he participated in several team community relations events this summer. That doesn’t happen for training camp invites, only Tacko.

So it’s time for the Celtics to figure out a way. You don’t discard players with Fall’s height and upside, because he is proving to be a capable player. The Celtics’ 15th man or two-way contract player won’t determine whether the team reaches the NBA Finals. It’s a development spot.

And it’s a perfect opportunity for Fall and the Celtics.