WALTHAM -- It wasn't exactly hard to tell. The Celtics dropped their fourth game in a row and their 17th of the season, and Rajon Rondo was wearing the loss all over his face as he sat with a blank stare on a stack of exercise mats waiting for practice to start Thursday afternoon.
This isn't something he's used to. This isn't something he's trying to get used to.
Not counting his rookie season, Rondo could count the number of times he had experienced a three-game losing streak on two hands before this year.
But this is the second time the Celtics have lost at least three-straight games this season with eight losses in their past 10 games. They haven't went on a run longer than the three games they strung together in mid-November against the Bucks, Bulls and Jazz. They haven't won back-to-back games since they beat the Sixers on Dec. 8 and the Mavericks in overtime four days later.
For all the talk about schemes and rotations and trust and execution, Rondo put it as simply as possible.
"The frustrating part is just losing," he said. "I'm a sore loser. It's tough to lose."
Then he put it in broader terms.
"Everybody isn't," he said. "You'll learn that everybody isn't a sore loser. Some teams are OK with losing. Some guys are OK with just getting a check. But everything I do, I compete. So, this four-game losing streak is frustrating."
He stopped short of pointing fingers.
“I can only judge myself,” Rondo said. “That's my New Year's resolution. I don't want to judge anybody this year.”
But his message was clear.
A year ago, the Celtics started the season with a three-game losing streak and suffered two different five game skids, but otherwise never lost more than two in a row.
The 2010-11 Celtics never lost more than two straight games. The 2009-10 Celtics went on four different three-game dives but were able to stop the bleeding there. In 2008-09, right after the Celtics went on a 19-game tear, the Celtics lost seven of their next nine including four straight during one stretch but that was easily the most turbulence they ran into all year.
In 2007-08, when the C's regular season was essentially a yellow brick road, they lost three straight games in February, giving up 100-plus to New York and Golden State then being held to 77 by -- wait for it -- the Phoenix Suns.
None of the players who were at the team's core through those seasons swallow losses well. At different points this season, Kevin Garnett has made it clear that he didn't sign a three-year, $34 million deal over the summer to "go through the motions."
After watching the Warriors light them up Dec. 29, Garnett again said, "we've never been a go-through the motions team, and I don't think we're going to start. I didn't come back (for an 18th season) to go through the motions. I don't think the guys who signed came here to go through the motions."
There's no connection between how much a player sulks and how much he cares about a loss, head coach Doc Rivers said, so he doesn't read into reactions after losses.
"You've still got to learn from losing and learn from winning at the same time," Rivers said. "Clearly there are guys that are more emotional than others. That doesn't mean the other guys don't take it just as poorly."
Still, it's a place the Celtics are used to being in and have no desire to be stuck in.
"You go through adversity every season," Rondo said. "It's nothing to get too down about. It's a long season. I'm staying positive. I haven't lost faith or hope in this team. I still have high expectations. I know we will turn it around."