WALTHAM — Kendrick Perkins  always looks like a man who gets no respect. He wears the same scowl on his face whether he’s happy or mad. That scowl is what makes opposing fans dislike him and probably doesn’t help his cause with the referees either, to whom he is also constantly showing that same sour puss.
Perkins was left off the NBA’s All-Defensive Team for the second straight season and Doc Rivers  joked that maybe that look turned some voters off.
“Well, I guess it’s going to continue to happen,” Perkins said. “Because I ain’t changing the way I look.”
That was a joke in case you needed context and Perkins had a few ready Thursday after he returned to practice with a hyperextended right knee.
His reaction to getting six stitches in his lip courtesy of Shaquille O’Neal ?
“Man, I look at it like I’m already ugly,” he said. “I can’t add nothing else to that, man.”
Perkins defense on Shaq has been no laughing matter. After holding Jermaine O’Neal  to 9-for-44 shooting in the first round against Miami, Perkins has kept Shaq in check (8-for-22, 20 points in two games). His one-on-one defense in the post is vital because the Celtics  feel like they can’t afford to offer help on the Cavs post players.
It’s that ability play imposing post players without help that has begun to make Perkins’ reputation.
“I don’t see why he doesn’t get enough votes for the All-Defensive Team,” Rivers said. “I don’t know if there’s a better on-man defender in the league than Perk at the 5-spot.”
High praise, especially for a player who came into the league with all of the physical tools, but who had to learn from scratch the basics of footwork and positioning. Perkins said that he’s learned from his veteran teammates and included a surprising former mentor.
“I take bits and piece from a lot of guys,” he said. “I watch how [Kevin Garnett ] guards some guys. I take a little bit from him. Little bit from Rasheed. I learned some things from Mark Blount too, believe it or not.”
Still, whether he gets respect or not, Perkins is fully confident in his abilities.
“It’s disappointing a little bit because you feel like you can defend better than half of those guys that made it,” Perkins said. “But at the same time, give credit to them for making it.”