We tend to think that the first two months of the NBA season don't matter much. After all, there's still another four months to turn it around. We just ignore these results, often while focusing on football. However, the games count the same. Records still count after Christmas, and more importantly, even if you can change or evolve your identity, it still exists going deeper into the season.

Take the Celtics, for example. They fell to the Raptors 101-94 on Friday night. It was a quiet December game, and Isaiah Thomas didn't play. Boston remains 13-10, and still a top-4 seed in the East. It's not a huge deal. But it's notable that it is now the fifth time the Celtics fell to a team with a top-tier winning percentage, and the Boston Globe notes that's getting to be an elephant in the room with these Celtics.

Entering Friday, the Celtics had faced the Cavaliers, Warriors, Spurs, and Rockets -- all teams with winning percentages of .680 or higher -- and they had lost to all of them. And this night, against another powerhouse, was no different, as the Raptors used a devastating third-quarter run to take a 101-94 win at TD Garden.

There are plenty of convenient excuses for these struggles. The Celtics were missing Al Horford and Jae Crowder in two of the losses. On Friday, they were without their injured All-Star point guard, Isaiah Thomas.

But the Raptors also could point out that they were without starting forward DeMarre Carroll, or that they had played on Thursday night while the Celtics rested.

Or they could just come into Boston, control the second half, and leave with yet another win, which is exactly what they did.

The five elite teams the Celtics have fallen to this season have lost a combined 27 times. Some teams with inferior records are finding ways to beat these squads, even if only occasionally. If Boston wishes to ascend, it must find a way, too."

We still have a ways to go," Celtics coach Brad Stevens said, "and I think it's something where we have to keep working to get to the point where we are so good at controlling what we can for 48 minutes, because we've talked about it many times. If we play well against anyone in the league, we have a chance to win. If we don't play well, we'll lose, and that's just the way it is."

Source: Raptors use devastating third-quarter run to squash Celtics.

This is complicated, more so than it looks on the surface. We tend to look at games like this and say "Oh, they were without (X key player), so it's OK." Except that teams win these games all the time. In fact, if you notice, any injured team winds up being competitive or winning often, in part because it's difficult for the opponent to get up for that game, and the injured team feels that "up against the wall" sense. You can say "they're professionals, this is unacceptable," but it happens so often, and whether it should or should not, it's a thing.

Isaiah Thomas' absence is actually not as big a factor for Boston as one would believe. USATSI

Take the Grizzlies. They're without Mike Conley, their best player, Chandler Parsons, their third-best player, Vince Carter, their sixth-best player and James Ennis, their seventh-best player. Yet they're on a five-game winning streak after beating Portland Friday.

Those same Grizzlies were blown out by Toronto in the first game after Conley's injury.

Next, we need to note a weird statistical quirk with Isaiah Thomas. The Celtics beat their opponent by one point per 100 possessions with Thomas on the court. That's really low for an All-Star. Next, they beat their opponents by 3.9 points more per 100 possessions with Thomas off-court. This doesn't mean that Thomas isn't good; he definitely is. But given that information, shouldn't they be able to survive without Thomas, given that they've been better as a team when he's not on the court?

You can point to the injuries, but one of the strengths of the Celtics is their bench. With starters injured, that's meant good players would step in, right?

Here's the biggest thing, however: every team has injuries. You're going to have to be able to win games without them. The Celtics have won games against bad teams with injuries, but don't have many signature wins. When they get healthy, they could, but these games, particularly the ones vs. Eastern Conference opponents, gain emphasis and it means there has to be more pressure to win those in the future.

In short, some teams' overall strength is enough to sustain through injuries, and so far, the Celtics' hasn't.

That's one perspective. But you need to keep the alternative in mind, as well.

Thomas isn't just their best player, he's also hugely responsible for their offensive success. He's their leader in points and assists, and most importantly, in a game that was tight down the stretch, they were missing their biggest clutch performer against the Raptors. Al Horford is their best defender, big man and third-best scorer. He's also their best screener. He unlocks much of what they do. And the Celtics' defense hinges on great perimeter defense from Jae Crowder, who missed a big chunk of games early on.

Every team has injuries, but if you're the Celtics, you're focused on what you can do if you get fully healthy. You can't control whether injuries happen, beyond precautionary measures. What are they capable of at full strength? We still don't know the answer to that question, and we have plenty of time to find out.

So to sum up, it's fair to say that the Celtics haven't lived up to expectations, and even with their record, haven't been an impressive team this season. It's also fair to say we're a long way from knowing what they're best looks like. They can beat great teams (if not elite ones) when at full strength. They look that good on paper. Now it's a matter of finding out whether they will live up to that potential or not.

(One more note, lost in this? The Raptors are clearly the East's second-best team and on a tier of their own behind Cleveland. That's the part that most often gets missed in this kind of analysis. Everyone was ready to toss the Raptors away for the shiny new Celtics, but the Raptors are a proven commodity and they're just doing what they do: win a ton of games.)