LAS VEGAS — The NBA’s Board of Governors approved a number of changes for the 2017-18 season designed to improve game flow, and the Celtics will get to try them out overseas.

According to involved sources, the Celts will meet the 76ers in London next January. The schedule for the coming season is expected to be released next month, with the league’s Global Games potentially being announced prior to that.

The Celtics-Philadelphia matchup will be a regular season affair — not an exhibition — and will be a 76ers home game. That means Philly fans will have one fewer opportunity to see Jayson Tatum and Markelle Fultz, the third and first overall picks from last month’s draft, respectively, involved in the major pre-draft trade between the clubs.

The game will be on Thursday, Jan. 11, at The O2 Arena, the same site where the Celtics met Minnesota in a preseason game in October 2007.

The upcoming season will begin earlier and have fewer exhibition games as the league attempts to cut down on player fatigue by stretching the schedule over more days. Veterans have to report by Sept. 25, and the regular season will open a week earlier than usual on Oct. 17.

Once the games begin, the most visible changes will be in a quicker pace to the last few minutes. Teams will have seven timeouts per game instead of nine, and they may now use just two timeouts in the last three minutes of a game, rather than the previous allowance of as many as three per team in the last two minutes.

And say goodbye to 20-second timeouts. All breaks will now be 75 seconds, where previously full timeouts had been 90 seconds and the so-called 20-second timeouts were actually 60 seconds in length.

Commissioner Adam Silver said the length of games has already been cut back “from around 2 hours and 23 minutes or so to about 2 hours and 15 minutes. We’re pretty happy with the length of the game.

“We were more focused here on the pace and flow of the game,” he said. “What we heard from our fans and heard from many of our teams was that the end of the games in particular were too choppy. I think since I was a kid, that’s an issue people have been talking about, the last two minutes of our game. We think these new changes will have a significant impact, especially at the end of the game. Overall, we’ve gone from 18 to 14 timeouts.”

There can, of course, still be additional stoppages in play late in games if replays are warranted, but the league is hoping the fewer timeouts will make for fewer stops and starts. Additionally, halftime breaks will be more uniform, with the 15-minute countdown beginning immediately after the second period concludes.

Another change may cut down on the stress for fans and teams and for players potentially on the block. The February trade deadline will now be the Thursday 10 days prior to the All-Star Game rather than the Thursday four days after. This season’s deadline will be Feb. 8.

“The motivation for moving the trade deadline before All-Star was the sense that it was more unsettling to have a player traded right after the All-Star break, that the All-Star break would have been an opportunity for the player to move himself, his family, get his family readjusted and get readjusted to the new team when they have that four- or five-day period to do that,” Silver said. “So it was really no magic to it. It was something we’ve discussed for several years.”

If a player scheduled to appear in the All-Star Game should be traded to the opposite conference, Silver said it was decided that “rather than having a hard-and-fast rule, let’s make the decision at the time. . . . We’ll deal with it when it happens.”

There was also some discussion, with the balance of power having shifted strongly to the Western Conference, of seeding playoff teams 1 through 16 regardless of geography. But, according to sources, there are simply not enough votes to support such a change.

“We considered it fairly thoroughly about two years ago through a committee process and at the Board of Governors meeting, and ultimately we concluded that given all the focus on sports science, health of our players, impact of travel, it didn’t make sense, at least at this time, to move to a balanced schedule, because again, we play an imbalanced schedule,” Silver said. “Teams in the East obviously play each other more than teams in the West, and the notion is if you’re going to seed 1 through 16, the only fair way to do it is then have a balanced schedule throughout the season.

“So ultimately I don’t recall the precise calculations, but it resulted in significantly more travel for our teams, especially for those teams on the coast. The conclusion was that at least given the state of travel, the state of science on travel, we’re better off staying in the conference system the way we have it, and of course same implications for the playoffs.

“The notion, again, of having teams crisscrossing the country in the first round didn’t seem to make sense to our teams.”