Robert Williams, the Boston Celtics' first-round selection in the 2018 draft, admitted he overslept the team's originally scheduled introductory conference call on Friday morning, although the team believes it was simply a miscommunication compounded by different time zones.

Williams, a projected lottery pick, did not attend the draft in New York and instead spent Thursday with family in his native Louisiana, where he watched the draft from a party at a Buffalo Wild Wings.

The Celtics snagged Williams with the No. 27 pick but ran into troubles trying to get him on the phone in the aftermath of the selection, including with Friday's 11 a.m. EST call.

"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 Friday afternoon in a call that took place an hour later than originally scheduled. "When I woke up, my sister woke me up, she said, 'You have a conference call.'"

Williams later noted that it was, "a good night's sleep after a busy two days."

The Celtics were not concerned about the missed call, in part because of the time difference. Poor audio hindered the follow-up call as Williams' phone broke up repeatedly while answering questions during a 10-minute session with reporters.

The Celtics plan to formally introduce Williams next Friday in Boston.

Williams, an athletic 6-foot-10 big man out of Texas A&M, was ranked No. 12 on ESPN's final predraft big board, but there were concerns about both a knee injury and his approach to the game. Missing the initial call, accidental or otherwise, did not seemingly help dispel some of those concerns as social media had a field day with his absence.

The Celtics were deemed one of the night's winners after Williams slid to them. Williams seems to already have motivation from those that doubt him, especially after falling in the first round.

"You always have people that doubt you," said Williams. "I know that I'm definitely going to make a lot of noise when I get there."

Some wondered if Williams hurt his stock by returning for a sophomore season with the Aggies, but he said he does not second-guess his decision.

"Definitely no regrets," said Williams. "I definitely feel like everything happens for a reason."

Williams called it a blessing to land in Boston and said he's eager to learn from a veteran like Al Horford. He praised Boston's young core, including Jayson Tatum and Jaylen Brown.

And Williams said it will be his defense that distinguishes him at the next level.

"I feel like I love defense," said Williams. "I feel like most of all I thrive off defense, a defensive stopper. And I feel like the energy the Celtics have on defense is the excitement -- from simple hustle plays, as far as diving on the floor for the ball. It really gets the team and the fans going. And I feel like I can definitely bring a lot of energy from that perspective."