The NBA season will be here before you know it and FanSided is here to get you ready. In the lead up to Opening Night, we’ll be previewing two teams each day, reviewing roster changes, discussing important players and challenges, and hearing the perspective of our FanSided site experts. Let’s get ready for basketball!

Roster changes

Inputs: Jaylen Brown (SF, NBA Draft pick No. 3); Demetrius Jackson (PG, NBA Draft pick No. 45); Ben Bentil (PF, NBA Draft pick No. 51); Abdel Nader (SF, NBA Draft pick No. 58); Al Horford (C, signed for four years, $113 million); Gerald Green (SF, signed for one year, $1.4 million)

Outputs: Evan Turner (SG, signed with the Portland Trail Blazers); Jared Sullinger (PF, signed with the Toronto Raptors),

Retained: Tyler Zeller (C, signed for two years, $16 million)

Most important addition

Al Horford isn’t a “superstar” in the traditional sense, but he certainly plays like one. The Celtics have failed to lure a top-flight free agent for decades, but that all changed in the summer of 2016, as Danny Ainge and company convinced Horford to bolt from a very safe place in Atlanta to take over the reins as Boston’s top asset.

As previously noted, Horford’s non-traditional superstar makeup often throws fans off the scent of his greatness, but Boston certainly recognizes it. Horford is a devastating offensive force given his shooting acumen, passing ability and overall acumen but, perhaps more importantly, he arrives as the defensive anchor that this team lacked a season ago with players like Jared Sullinger and Kelly Olynyk seeing extended time in sub-optimal positions.

Horford is not going to average 20 points and 10 rebounds and, because of that, there will almost certainly be a segment of the basketball-watching population that writes off his four-year max contract as a “miss” for the Celtics. What Horford will do, though, is provide above-average play at both ends of the court, leadership in the locker room and another level of credibility for a franchise that has visions of taking on the Cleveland Cavaliers with the Eastern Conference crown on the line in May.

Biggest strength

The Celtics managed to claim 48 victories a year ago, and they did it without the benefit of a single top-30 player (sorry, Isaiah Thomas) in the NBA on the roster. Boston did have some roster strengths in that Danny Ainge put together a (very) deep group that was adaptable to many different styles of play but, in the end, the biggest portion of the credit for the team’s success goes to head coach Brad Stevens.

Stevens may not be the best head coach in the sport, simply because San Antonio’s Gregg Popovich still exists as perhaps the best the NBA has seen in the job. However, the former Butler wunderkind has greatly aided in Boston’s transformation from also-ran to Eastern Conference contender, and Stevens regularly manages to extract maximum value out of his players.

Evan Turner’s play a season ago is just one example of the type of wizardry occurring in Boston, and Stevens will have the opportunity to mold the likes of Marcus Smart, Jaylen Brown and others in 2016-2017. Throw in the fact that the Celtics now have a legitimate “number one” in Al Horford, and the NBA should have a healthy level of fear given that Brad Stevens strolls along the sideline for the Celtics.

What does success look like?

— Jeremy Karll, @HoudiniCeltics, Hardwood Houdini

The Boston Celtics were one of the busiest teams this summer. Despite their inability to trade for a star, or at least an upgrade in their front court, they added a star big man in free agent Al Horford. That addition, along with third overall pick Jaylen Brown and sharpshooter Gerald Green, gives Boston a chance to once again be one of the top teams in the East.

That being said, hanging with the Cavaliers and knocking them out of the playoffs in a seven game series isn’t likely at this point. Sure, Horford adds a dynamic to their offense and defense that wasn’t there last year, not to mention somewhat stabilizing their front court. Although, Brad Stevens has still never won a playoff series and this is a team who is coming off a first round loss, with very little playoff experience.

Even if beating Cleveland isn’t realistic this year, I think anything less than at least a playoff series win would be very disappointing. While the Eastern Conference Finals should be their goal, there are still a lot of questions surrounding this team that could hinder that plan. Everyone is hoping they take another huge step, but realistically, this team needs to continue to take baby steps and prove that they can win in the playoffs.