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When the Oklahoma City Thunder announced on Tuesday afternoon that Shai Gilgeous-Alexander would be out for their matchup with the league-leading Boston Celtics due to an illness, all signs pointed to a blowout. That was indeed what happened, just not in the way everyone expected. The Thunder embarrassed the Celtics setting a new franchise record for points in a 150-117 win. 

The 33-point defeat was the worst for the Celtics since Jan. 31, 2003, when the Detroit Pistons crushed them by 52 points. In addition, it was just the second time in franchise history that the Celtics allowed five 20-point scorers in the same game; Josh Giddey (25), Luguentz Dort (23), Tre Mann (21), Jalen Williams (21) and Isaiah Joe (21) combined to nearly match the Celtics by themselves. 

Strange losses will happen over the course of the season, but even more worrying than the result were some of the quotes coming out of the Celtics' locker room. 

"We got our ass kicked, that's what happened," Jaylen Brown said. "You come out and take it for granted, that's what happened. We probably had it coming to us. We came out the last couple of games. We pick and choose when we want to play. We wasn't connected, didn't have each other's back out there, no help-side defense, we didn't guard our yard. Those young boys over there came out and they made us look bad. They embarrassed us, they kicked our ass. That's what happened."

"We took a deep breath and relaxed [when we heard that Gilgeous-Alexander would be out], Malcolm Brogdon said. "Honestly we should know better than to come out and not play with aggression, not play with energy and urgency."

The Celtics got off to a flying start this season, and after a 27-point destruction of the Phoenix Suns on the road were 21-5 with an offense on pace to smash all sorts of records. Since then they are 5-7 with losses to the Orlando Magic (twice), Indiana Pacers and now the Thunder. Their lead for the best record in both the league and the Eastern Conference is down to half a game over the surging Brooklyn Nets

Some of that is down to bad luck in the shooting department. Over the last 12 games, the Milwaukee Bucks are the only team generating more wide-open 3s per game than the Celtics' 21.6. However, the Celtics are making just 31.3 percent of those shots, which is the third-worst percentage in the league over that span. At the same time, opponents are shooting 44.7 percent on their wide-open 3s, which is the third-highest opponent percentage in that time. 

But as Brad Stevens said during a press conference last month, "the easiest thing in the world to do is point to shooting variance," and the Celtics' struggles are about more than just bad shooting. They can't rely on their defense every night like they could last season, they don't rebound well, especially when Robert Williams III isn't in the game, and don't get enough easy points to fight through cold shooting stretches. 

More than anything, though, they've taken their foot off the gas. Nothing made that more clear than Tuesday's result and the quotes from Brown and Brogdon. Perhaps that's understandable considering the grind of the regular season; maintaining a 66-win pace (something only 17 teams in the history of the league have ever done) was always going to be a lot to ask even with this team's talent and roster balance.

The problem with coasting is that it can then be hard to find that top gear again on a consistent basis, which is something the Celtics are clearly struggling with right now.  

"You're not supposed to let that happen," Brown said. "Whatever that means, whatever you gotta do, you can't let that happen. It just seemed like for whatever reason today, we let go of the rope completely, which I haven't seen from our team in a long time. So whatever we've got to do to get back on track, let's all get back on board."

The Celtics' next game, a national TV showdown against Luka Doncic and the red-hot Dallas Mavericks on Thursday night, will provide the perfect opportunity to do just that.