He wasn't, and that's in part why steely cool Brad Stevens (and Gerald Wallace) were ejected soon after. But let's keep the focus on Humphries.
Making a spot start in place of Jared Sullinger (out with a concussion), Humphries turned in a gritty 36½ minutes, most of which were spent riling up Cousins with good old-fashioned grit and physicality.
After Cousins went for 31 points and 16 rebounds during the teams' first meeting in Boston, Humphries limited one of the league's more talented young big men to 13 points and seven rebounds over 34 minutes. Humphries clearly got under Cousins' skin by refusing to back down to his physical play.
Late in the first half, Cousins confronted Humphries between free throws, leading to double technicals when Humphries shoved Cousins back toward the opposite blocks. Humphries didn't let that faze him, refusing to budge to a player that leads the NBA with 13 technical fouls.
And that's part of the reason why Humphries has become so revered this season. Those who previously judged him solely from his reality TV cameos -- or last season's dust-up with Rajon Rondo that left Boston's point guard suspended -- have reversed course based on his work ethic and style of play.
Every team needs a player like Humphries. Boston's logjam at the power forward spot has made it difficult at times to carve out consistent minutes, but Humphries' effort has never wavered. With a team-high $12 million contract, he'd be a lightning rod if it weren't for how hard he works during games (and after practice with younger players), doing all he can to provide a quality veteran presence despite an uncertain future.
Humphries will be an unrestricted free agent after this season. Given the way he has played -- and having expressed a desire to stick around -- the Celtics will investigate the potential to retain him at a less gaudy salary. But even if that fails, Humphries still could aid the Celtics' transition process as a sign-and-trade asset.
During Saturday's loss in Sacramento, Humphries reminded everyone that he's not quite the consistent double-double player we saw for a couple of seasons in New Jersey, but he brings a lot of positives to a team that can't quite be quantified in a box score.
Humphries' basic stat line doesn't leap off the page this season: 7.8 points and 5.7 rebounds over 19.2 minutes per game. But Humphries' PER (17.8) is on par with his best individual seasons with the Nets, his field goal percentage (50.5 percent) and his block percentage are both career highs. What's more, Boston is simply a more efficient team when he's on the court (2 points better per 100 possessions offensively with Humphries; 0.6 points better defensively).
Dig deeper into his individual numbers and Humphries' season looks even better. Offensively, he's averaging 0.969 points per play, which ranks in the 72nd percentile among all league players, according to Synergy Sports data. Humphries' score percentage (total number of plays that finish by generating at least a point) is a team-best 49.6 percent. For comparison's sake, Jeff Green is at 41.6 percent and Jared Sullinger is at 41.9.
On the defensive end, Humphries is allowing 0.801 points per play, which ranks in the 76th percentile among all players and is second best on Boston's roster behind only Sullinger (0.771).
Sullinger's second-year emergence and a need to generate more minutes for rookie Kelly Olynyk have made it difficult for first-year coach Brad Stevens to get Humphries quality minutes. But Saturday's game again showed how Humphries has stayed ready. With Sullinger a late scratch, Humphries stepped in and antagonized Cousins.
Cousins finished 2-for-4 shooting for only four points when matched up with Humphries, according to Synergy data.
Mix in his consistent midrange jump shot at the other end of the floor and even Kings coach Mike Malone admitted, "[Humphries] did a good job at being very physical and pushing DeMarcus Cousins out. He forced Cousins into a couple of turnovers. He had a good game. You don't plan for him to have that many jump shots but, to his credit, he had it going tonight."
Cousins wouldn't even acknowledge Humphries by name when asked about him after the game; Humphries returned the favor by no-commenting a question about his matchup with Cousins.
One topic Humphries hasn't shied away from is his desire to return to Boston next season. That could hinge on how much cap space the Celtics free up at power forward, and the type of interest Humphries draws on the open market. But Humphries, who just turned 29 and is playing his 10th season, has stressed that he sees what Boston is building toward.
Many veterans would run the other way when faced with the adversity of a rebuild. Some would cash a check and turn in the bare minimum effort. Humphries said before the All-Star break that anyone who entered with the expectation of Boston being 17 games under .500 at this point had a "loser" mentality.
Humphries knows only one speed. He showed it Saturday against Cousins and the Kings. And, one way or another, he's likely going to continue helping the Celtics after this season because of the way he plays.