Robb: Robert Williams III checks a lot of boxes for the Celtics at No. 27

The 2018 NBA Draft class had plenty of impressive bigs, but most of them weren’t expected to be available at the No. 27 pick, certainly not the athletic ones. Yet, the Celtics had one fall into their lap on Thursday night as Robert Williams III, a 6-foot-9 athletic phenom slipped after being projected to go in the teens by most top draft experts over the past week.

The scouting report on Williams III is a simple one. It's easy to compare his long-term potential to guys like Brandan Wright, DeAndre Jordan or Clint Capela. He can block shots and finish lobs with the best of them at the collegiate level and also struggles with his free-throw shooting and outside shot (he only hit one 3-pointer in his two seasons at Texas A&M).

So how exactly does he fit into a Celtics team that already has established bigs in place during the rotation?

The match is better than you think.

Needed young depth up front

The Celtics were always a bit thin in the frontcourt during the first half of last year. Al Horford, Aron Baynes and Daniel Theis were reliable pieces but there were no true bigs that they could trust behind them to protect the paint and rebound. That vulnerability led to the signing of Greg Monroe in February with the disabled player exception as big insurance, which proved to be needed immediately once Theis went down for the season.

With Monroe unlikely to return to Boston for obvious reasons (his defensive issues/lack of playing time), the C’s needed some big man depth behind their regulars. They don’t have much money to spend in free agency and it would be tough to convince a veteran to take an end of the bench role for a limited payday. The likes of Nerlens Noel and Dwight Howard aren’t going to take short money in Boston to play short minutes. They’re going to want opportunity.

The ideal alternative is a young guy who needs some seasoning and also fills a need. Williams is a true big that fits that bill. He will get a chance to grow now under the guidance of Al Horford and potentially Aron Baynes, as well to develop into an elite defender over time. In the meantime, he checks off a box on the depth chart needs.

“I think with all young players at whatever position,” Danny Ainge said of Williams' development, “I think it’s just easier to play with veteran players that know how to play, a coach that knows what your strengths and weaknesses are and puts you in position to succeed, places where you can succeed. I think that will help him tremendously. He doesn’t have to try to do too much out of the gate and just do what he does well.”

A different element for a Boston big

Williams comes with his fair share of warts as a player. He was suspended for a few games last season. He has questions marks about his motor when he’s on the floor. All of these issues and his limitations as a shooter on the offensive end helped lead to his freefall to No. 27. Still, there is no question he gives something the Celtics haven’t had during the Brad Stevens era: A big man that can jump out of the gym.

His size (6-foot-9), wingspan (7-foot-5), standing reach (9-foot-4) and overall athleticism helped make him a two-time defensive player of the year in the SEC. He’s a monster shot blocker and great finisher on lobs.

“He was a player that we liked coming into this draft process,” Ainge explained. “He’s a rim protector and rebounder, and a guy who can play above the rim on both ends of the court. We don’t have much of that. We have a little bit of that, but not what he can do. So his abilities to protect the rim, and rebound, and run the floor, and I think are some of his greatest traits and uses.”

Finishing around the basket was an issue for most of Boston’s roster throughout last season, so bringing aboard a player that forces the defense to pull in towards the rim should be a valuable dynamic that Stevens can use situationally around plenty of outside shooting.

“Obviously, if you can have four shooters on the floor and a guy like that rolling to the rim, you can just throw it up in the air and go get it, finish it,” Brad Stevens said. “And I think that there’s a lot of things that he brings to the table, but those are the things that translate sooner rather than later. As he continues to improve and improve his skill and everything else, we’ll see where all that goes. But right now, he is an elite athlete and with incredible length.”

“We feel good about adding one positional player that has something that we don't have,” Ainge added, “that does something that we don't have,”

A pricey trade market keeps Celtics at No. 27

The Celtics weren’t content to stay at No. 27 all night long. Ainge acknowledged that the team was active in looking for deals ahead of the draft and on draft night itself. Still, in an offseason where a lot of teams don’t have cap space to make major additions to the roster, draft picks were held in high regard by most franchises around the league. That factor made it prohibitive for Boston to jump up.

“We had spent the last few weeks trying to figure out what the cost was to get into the top of the draft,” Ainge said. “We knew going into today that it was very, very unlikely that was going to happen. We were preparing for the 27th pick in the draft and we were preparing for opportunities to move up, not all the way to the top of the draft, but somewhere in the middle of the draft. We were even preparing for opportunities if guys we didn't like were (at No. 27) and moving backward in the draft. That's the same thing we do every year in the draft with any situation that comes up.”

The end result is still a promising situation for the Celtics. They found a guy with high upside at the tail end of the first round and still have their cupboard full of assets intact. Bringing back rotation pieces like Terry Rozier and Marcus Morris should hold plenty of appeal for a team with title aspirations next season. Williams III doesn’t push out any of those pieces, he just gives Stevens another lineup look to work from as the season progresses. The 20-year-old may very well end up spending more time with the Maine Red Claws instead of the Celtics next season anyway, depending on health and his NBA readiness. He can't shoot 3-pointers and free throws (46 percent). His motor is inconsistent. There are some off-court issues that led to a suspension last season for a couple of games.

It's easy to overlook those issues when drafting at No. 27 overall. Williams III has the physical tools to be great. It could take a couple years, but Stevens should have a good chance to pull the best out of him.