5 big questions facing the Celtics this season

A look at five important issues facing the Celtics as the team tips off their 2017-18 campaign on Tuesday night:

1. How much has the defensive rebounding improved? Death, taxes and the Celtics struggling on the glass are three things fans have been able to count on during the Brad Stevens era. Of late, Danny Ainge has focused more on having better all-around bigs that can spread the floor offensively, even if it comes at the expense of cleaning up the glass. However, the Celtics did well this offseason to make some improvements in this area from a length perspective. Aron Baynes is the best natural big-man rebounder the team has had in years. Jayson Tatum is an above-average defensive rebounder for his size. Gordon Hayward has added size on the wing that should translate into better support for Boston’s bigs on the boards. Will these additions be enough to pull Boston out of the basement in defensive rebounding rate (28th last season)? The preseason returns were encouraging, but we’ll find out this week.

2. Which young guys can hit open jumpers? After chatting with several members of the front office over the course of training camp, this was the issue that came up most often. The Celtics lost a lot of reliable elite shooting last year (Avery Bradley, Jae Crowder, Kelly Olynyk, Isaiah Thomas) and replaced the majority of it with unproven youth. There will be a bevy of open looks available all year long for role players, thanks to creators like Gordon Hayward and Kyrie Irving. But the mystery remains: Which Celtic(s) will prove themselves as trustworthy from beyond the arc? We saw hot hands from Marcus Smart and Terry Rozier this preseason, but defenses won’t respect their iffy track records until they prove they can hit those shots in the regular season. Brown (18 percent in preseason) and Tatum (33 percent in preseason) will be put to the test immediately on the perimeter with the starting five as defenses sag off both. Mystery contributors (Semi Ojeleye?) could emerge as factors as well if he proves to be capable from deep. Stevens is going to have to find someone to trust in this department to maximize the offense and that process might take a little while.

3. Will starting lineup-by-committee actually work? In theory, the idea makes plenty of sense, and fits the personnel on the Celtics roster. Starting Baynes makes sense against guys like Dwight Howard, Jonas Valancunias and Hassan Whiteside but isn’t necessary against a more stretchy lineups (like Kevin Love playing center for the Cavs). Stevens has emphasized his team needs to be flexible all year long with lineups, but NBA players are creatures of habit. They like routine and want to know when they're playing. This concept could disrupt those certainties a little bit. However, I’m a big believer this idea will work with buy-in from the players. Baynes is a team-first guy, Smart has already volunteered to come off the bench and Tatum is just a rookie, so he should be happy no matter what Stevens does with him on a 50-plus win team. Will Smart push to start more now with no extension in place? Will the team fare better mixing it up every night? These issues all bear close watching as the season begins and when Marcus Morris returns to the fold.

4. Who can the Celtics trust defensively? Smart. Horford. Hayward. Baynes. Morris. Those are five players Stevens can trust, but they probably won’t see any time together as a unit on the floor all year. After those guys, the list gets a little bit murky for Boston, and that’s concerning for a team that wants to play plenty of small-ball this year. That’s not to say this will be a below-average defensive team. Tatum is ahead of where he should be as a rookie. Brown has shown progress in limiting opposing guards with his on-ball defense. Stevens has raved about Rozier’s off-season improvements as well. Who can step up to fill some of the void left behind by Avery Bradley and other castoffs?

5. Can Kyrie Irving live up to the hype? We know what to expect from Hayward and Horford on a nightly basis in Boston. Even if they don’t fill up the box score, they are going to be doing the little things to help the Celtics win on both ends of the floor. Irving’s offensive potential far exceeds both players, but it remains to be seen just how effective he can be in a leading role. The signs were promising in the preseason on this front. He was an eager passer, an efficient shooter and adjusted quite nicely to Stevens’s scheme. The pressure is on the 25-year-old All-Star though. This is his team now, and the Celtics paid off the Cavs quite handsomely with assets to give him this opportunity. Will he rise to the challenge and become a complete player on both ends? We will begin to find out Tuesday night in Cleveland.