Brad Stevens even admitted it: The Boston Celtics didn’t expect Robert Williams to be available at the No. 27 pick in the 2018 NBA Draft.

Which begs the question: Why did the Texas A&M product, projected by some to be a lottery pick, fall so far down the draft board?

ESPN’s Jeff Goodman provided some insight Friday morning, suggesting several teams had concerns about Williams’ injury history and had difficulty obtaining his medical records after he didn’t attend the NBA Draft Combine.

The concerns center around Williams’ knee, according to Goodman, who reported some clubs also had questions about the 20-year-old’s overall physical fitness.

One knock on Williams entering the draft was his occasional lack of motivation, so it appears that red flag could be warranted.

Celtics president of basketball operations Danny Ainge insisted the C’s did their homework on the 6-foot-9 big man, though.

“A lot of people that we talked to — his coaches, his teammates, his trainers — we check with a lot of people that are familiar with him, and everybody likes Robert,” Ainge said Thursday night after Boston drafted Williams.

Indeed, Ainge and his staff got a hold of Williams’ medical information and were reviewing it as the draft moved into the 20s, according to The Athletic’s Jared Weiss.

The Celtics obviously determined Williams’ upside outweighed his potential risks by nabbing him at the end of the first round. And while his Boston tenure didn’t get off to the smoothest start — he had to postpone his conference call with reporters Friday morning — the club’s competitors seem to think the C’s got a pretty good deal.

Thumbnail photo via C. Morgan Engel/USA TODAY Sports Images