Brad Stevens made his debut as the Boston Celtics' head coach in the preseason on Monday.

Stevens admitted he will need the entire preseason to adjust to the NBA, following a coaching career at Butler University.

"Really, really different," Stevens said. "Just because it's a 48-minute game, getting used to the timeouts... But, you know, it's a little unique; it's a little different. And I'll get used to those as we get on through. There's eight more minutes and a lot more possessions because of the 24-second clock, so getting a feel for that will hopefully -- I would like it to be done in the next seven [exhibition] games, but hopefully it doesn't last much longer than that.

"It is different. It's unique."