Who are the remaining options for the Celtics’ final open roster spot?

The options are dwindling. The Celtics have one more roster spot available, and we have to assume Danny Ainge has been quietly exploring the market for his final puzzle piece. But we’re only six days away from media day, and the free agency talent pool is becoming quickly desolate.

The Celtics were reportedly in on Andrew Bogut, but the 32-year-old veteran signed a one-year veteran minimum deal with the Lakers yesterday. Assuming that Boston offered Bogut a contract, this will be the second time in seven months that he has spurned the Celtics in favor of a team with more big man depth. Meanwhile, Tyler Zeller signed in Brooklyn, and basketball savant Boris Diaw is headed home to France.

What’s thinner—the current list of free agent big men, or the new Marcus Smart?

We’re just ahead of the start of training camp, and the projected rotation at the 5 spot remains a potentially important question for Danny Ainge. Aron Baynes is the team’s only true center, and Brad Stevens will prudently preserve Al Horford’s center minutes for only the critical moments. I wrote last week about the promise of newcomer combo big Daniel Theis, but it’s unfair to assume that the rookie can step right into a meaningful role on a team with championship aspirations. At this point, Boston appears comfortable with their ball handlers and wing depth, so the safe bet is that the final roster spot will go to a free agent big. Here are a couple options.

Thomas Robinson

The Celtics conducted a work out with Robinson a few weeks ago, but they haven’t shown any claim to him since the visit. Perhaps their lukewarm interest has grown cold. The journeyman combo big has played for six teams in five seasons, a tagline that has likely permeated into his reputation among league executives. But Robinson is only 26 years old and is fresh off of a season where he posted career highs in true shooting percentage (53.6) and PER (17.3). The 5th overall pick in 2012, Robinson still carries intriguing yet fleeting upside.

Robinson’s rebounding ability is the drawing point for Danny Ainge. Robinson sports an attractive 25.5% defensive rebound percentage for his career, per basketball-reference. It’s a tantalizing attribute for the Celtics, who were 29th in team defensive rebounding percentage last season. By comparison, Kelly Olynyk led Boston last season at 20.7% DRP. No other Celtic was over 20.0%. At 6’10” with a 7’1” wingspan, Robinson is a ball hawk on the glass and has a natural aptitude for tracking down seemingly impossible rebounds. Earlier this summer, Robinson told HoopsHype that he believes that he can be a top-10 rebounder if given the chance. Let’s not go overboard. His rebounding prowess is well-established.

Robinson’s rebounding might fill Boston’s biggest void, but he isn’t the ideal fit with Stevens’ system, at least not in last year’s system. Robinson can’t spread the floor at all. He’s 0-6 for his career from beyond the arc and took only 14 shots outside of the paint last season. In 2016, the Celtics heavily relied on their bigs to space the floor to open up driving room for Isaiah Thomas. Since then, they lost one of the better stretch bigs around in Olynyk and signed a conventional bruiser in Baynes. Stevens has earned a reputation as an innovator, one who can magically maximize the talent that he’s given, but adding another big with no shooting range would be a philosophical reversal from last season’s modernized offensive scheme. Here is Robinson’s 2016-17 shot chart with the Lakers, via NBASavant.

David Lee

I know what you’re thinking. Don’t tell me that the new writer is going to try to convince us on an aging veteran who disappointed Celtics fans a few years ago. Yes. It’s true. David Lee was not ready for the Boston spotlight in 2015. Coming off of an impact role with the NBA champion Warriors, Lee was advertised as a serviceable stopgap power forward who could start games and play effectively for around 20 minutes a night. Fans were tepidly enthusiastic about adding the one-time dominant double-double machine to the developing Celtics core. Reality works in bizarre ways. Lee ending up playing a total of 30 forgetful games in green before being waived and picked up by the Mavericks.

However, Lee has been quietly productive after his time in Boston, playing in 104 of a possible 107 games for Dallas and San Antonio. He’s coming off of worthwhile season averages of 7.3 PPG and 5.6 RPG over 18.7 MPG with the Spurs. Earlier this summer, Lee turned down a $1.7 million option in San Antonio, probably with the hope that his 12 years of NBA service will yield him a predetermined $2.33 million minimum deal.

You might attribute Lee’s high level performance to Gregg Popovich’s voodoo, but Lee appears to have some gas remaining in his tank. He’s still a solid facilitator from the high and low post and there isn’t another free agent who offers the same combination of high basketball IQ and a long-established résumé. Lee gives relentless effort on the glass and thrives in heavy ball movement systems like Boston’s. Now 34-years-old, Lee could provide an influx of energy if he plays 4-5 minute stints in each half.

A consummate professional, Lee has fit in seamlessly with every destination he’s been in (sans Boston), and a second chance with the Celtics in a reduced role could be the ideal situation for a veteran thirsting for another title run. As currently constructed, the Celtic roster is littered with inexperience. Eleven players are entering their fourth NBA season or less. Seven have never appeared in an NBA game. With the Celtics realistically on the cusp of another NBA finals appearance, adding a seasoned veteran like Lee could help to balance out a relatively untested second unit.

Exploring the scrapheap

Whoever the Celtics sign will be unexciting, so temper your expectations. If you arrive two hours late to a buffet meal, most of the preferred items will already be gone.

It’s mid-September, and the overwhelming majority of still available players are NBA fringe-level talent. Any worthwhile unsigned free agent is restricted and is probably midway through a negotiating showdown with his old team at a price point exceeding Boston’s budget. Ainge is working with only a minimum-level deal in hand. The ship has sailed on the possibility of a frontline veteran taking a discount to chase rings in Boston. Forget about any scenario similar to David West walking away from $11 million to play in San Antonio. There’s no one like that to be had. At this point, the hope is that the eventual signee won’t be forced into significant minutes during this season.

Additional notable unemployed big men include Lavoy Allen, Festus Ezeli, Tiago Splitter, and Jordan Hill. Adam Himmelsbach of the Boston Globe threw out the idea of re-signing Gerald Green, whose admirable postseason play should be enough earn him a spot somewhere. But as you can see, the list is pretty unappetizing.

All non-cited statistics are from basketball-reference.com

All free agency tracking news is from http://www.nba.com/freeagents/2017