WALTHAM, Mass. -- The Boston Celtics have a simple math problem: 16 guaranteed contracts and only 15 regular-season roster spots. But that's where the decision facing Celtics president of basketball operations Danny Ainge stops being simple.

By the end of this week, the Celtics must determine the least-painful path to pruning their roster -- and it might involve swallowing hard and cutting a recent first-round pick. For a team with elevated goals, including challenging the Cleveland Cavaliers for the top spot in the Eastern Conference, the hand-wringing over the final roster spot might seem trifling. But it's a bit more complicated because the Celtics yearn to squeeze every drop out of their recent draft-pick surplus.

The good news about the uncertainty at the back end of the Celtics' roster is that the front end is cemented. Boston's starting five, with offseason addition Al Horford joining Isaiah Thomas, Avery Bradley, Jae Crowder and Amir Johnson, has looked excellent in four preseason appearances.

There were concerns about Boston's bench with the departure of Evan Turner, but Marcus Smart and Terry Rozier have been two of the Celtics' best performers this preseason and rookie Jaylen Brown, the No. 3 pick in June's draft, has proved himself raw but ready for immediate playing time. When Kelly Olynyk is healthy enough to resume contact activities, the Celtics will have more than enough bodies to fill out a rotation that coach Brad Stevens says he'd like to keep at 10 (but we all know he's going to play 11 or 12 most nights).

So why the consternation over the young players who will essentially serve as emergency depth? Like most teams this time of year, the Celtics really like their young guys. They are curious to see how they evolve as NBA players and don't want to make the mistake of giving up on someone they've nurtured in the early stages of their pro careers.

Three players, two spots

The Celtics don't just have 16 fully guaranteed contracts, they also have a pretty sizable chunk of change ($250,000) committed to second-round draft pick Ben Bentil. Considering a $94.1 million salary cap, that partial guarantee ultimately amounts to pocket change and is the sort of money a team comfortably below the luxury tax can commit to help encourage a fringe roster player to accept the low wages associated with joining the team's D-League affiliate in Maine.

Even if they waived Bentil, the Celtics would still have three young players vying for two spots in third-year swingman James Young, second-year guard R.J. Hunter and rookie guard Demetrius Jackson. Boston knowingly put itself in this bind when it signed Jackson, the No. 45 pick in June's draft, to a four-year, $5.5 million contract in which the first year is fully guaranteed. The Celtics like Jackson, who is perceived to have slid on draft night, and would love to keep him in the sort of emergency ball-handler role that Phil Pressey held down in recent seasons.

Hunter, the No. 28 pick in the 2015 draft (a pick acquired from the Clippers when Doc Rivers fled west), and Young, the No. 17 pick in the 2014 draft (the first of three first-round picks acquired from the Brooklyn Nets in the Kevin Garnett/Paul Pierce trade) have struggled to distinguish themselves in limited NBA floor time and, making the team's decision that much harder, it's hard to project exactly how both players will ultimately pan out.

So what options do the Celtics have?

Swallow hard and eat a contract: The Celtics can afford to stomach the dead money that would result from waiving a player. The harder part is picking which one to move on from.

Find a trade: Ainge and his staff have already explored possible scenarios. The trouble with that route is that many teams find themselves in similar positions of trying to simply trim to 15 players. There might be teams willing to take a player, but with virtually no return for the Celtics. After all, why trade for someone who could ultimately be had on the free-agent scrap heap soon. Boston could send out money in hopes of recovering maybe a second-round pick at best.

The general consensus is that Boston's battle essentially comes down to Hunter versus Young. Veteran Gerald Green, signed to a minimum contract this summer, has proved he can help Boston's bench more than either player, securing his spot. (Plus, it would look bad if Boston let go a player who could have found other offers this summer.) Some have wondered if the team could find a way to move Tyler Zeller, but he's Boston's only pure big man and his salary -- non-guaranteed $8 million next year -- makes him a valuable trade asset further down the road. Jordan Mickey, a 2015 second-round pick, has shown enough -- at least last season in the D-League -- to be spared from the cut-down conversation.

The case for Hunter

In a preseason in which neither Hunter nor Young had previously made much of an in-game case for a roster spot, it was Hunter who finally stepped forward Saturday night with a team-high 17-point output in a 119-107 win over the New York Knicks.

It wasn't just the point total for Hunter, but how he scored. There were a couple of deep, quick-release 3-pointers and Hunter also wasn't bashful about going to the basket. In a 1-point game midway through the fourth quarter, he drove hard with a low shot clock, got bodied leaving the floor, and still muscled home a left-handed and-1 layup. Thomas spilled onto the court, flexing and screaming Hunter's name in celebration.

Hunter has also proved himself as a capable playmaker with a solid basketball IQ. He might not be a future point guard, but he has the potential to create off the dribble. The knock on Hunter, outside of his struggles to consistently make shots, has been his wiry frame. He's listed at 190 pounds and even Ainge has poked fun at his skinny legs. Hunter's ability to finish through contact was an encouraging sign that he's gaining strength, even it's not abundantly clear by looking at him.

While the 6-foot-5 Hunter still has progress to make as a defender, particularly trying to stay in front of opposing guards, he's at least embraced that side of the ball.

"[Defense has] been my main focus," Hunter said. "I think before I was coming in trying to figure out how to score, and now I’m just trying to figure out how I can help my team on the defensive end. I think that makes the offensive end a lot easier."

The case for Young

The 6-foot-6 Young has consistently bulked up since his arrival and now weighing about 230 pounds, he has the frame to play the wing position at the NBA level. He's been more consistent with his shot this preseason, making 44.4 percent of his 3-pointers.

Consider this, too: Young celebrated his 21st birthday in August, while Hunter will turn 23 before the start of the regular season. Although Hunter has seemingly nudged ahead with Saturday's outburst, it's fair to ponder where Young might be, developmentally, in two more years. (The trouble there is Young will be at the end of his rookie contract by that time.)

It's unlikely Ainge and his staff will get too caught up in draft position, but there is a difference between cutting a late first-round pick and someone who was nabbed just outside the lottery (with one of Brooklyn's picks, no less).

Young's defense remains a work in progress. Synergy Sports preseason numbers have opponents shooting 61.5 percent against him and generating 1.35 points per play (that ranks him in the 4th percentile among all NBA players this preseason). Young sits deep on a swingman depth chart in which Crowder and Brown are plus-defenders with an ability to shuffle to the power forward spot in Stevens' preferred small-ball lineups.

So what happens?

It's prudent to remember that, because of Boston's depth, it would seem a troubling sign if any of the players on the roster bubble factored heavily into the upcoming season. There's a line of thinking that should Boston gut its roster trying to add another star, one of these youngsters could step into a larger spotlight. But it seems safe to worry about that bridge when -- or if -- the Celtics cross it.

Remember, too, Boston could always punt on the Hunter/Young decision and simply waive Jackson while hoping no one else leaps on him at a time when the market will be saturated with available bodies after final cut-downs.

Regardless of the final decision, the Celtics will have far more pressing issues 48 hours later when the season tips off Oct. 26.