The first thing Robert Williams should buy with his new NBA contract is a nice, loud alarm clock.

The new Celtics big man, who was drafted with the 27th overall pick Thursday, missed his introductory conference call with media Friday at 11 a.m. ET because he was enjoying “a good night’s sleep" after watching the draft from a Buffalo Wild Wings in Shreveport, La.

"Right after the draft, I actually ran to my aunt's house and went to sleep because I was so tired from everything," Williams said on his rescheduled call (via masslive.com). "When I woke, my sister was like, 'You had a conference call.'"

Williams had some discipline issues at Texas A&M, including a two-game suspension to start the 2017-18 season for a "violation of university policy." His talent as a rim-running, shot-blocking big man had many project him as a possible lottery pick, but reported motivation issues may have caused his slide to Boston at No. 27.

However, Celtics GM Danny Ainge didn’t seem concerned after nabbing Williams.

"You never know everything about everybody obviously. We're comfortable with who he is and a lot of people that we talked to, his coaches and his teammates, his trainers," Ainge said. "I know that he's not perfect, but most players aren't and we think his upside -- he's got a great upside. We're very excited to have him. I'm not trying to defend our reason for drafting him, but we find he's going to be a good player."

Talented or not, Williams isn’t off to a great start in the NBA.