His left ankle, which will need surgery after the season, has plagued him for months. Then he injured his right ankle in Game 1 and lasted only 6:21 in Game 2.
Coach Rick Carlisle already has resigned himself to Howard's limitations. Howard, who did not talk with the media, sat out practice again Friday. He opted for treatment on his ankles, riding a stationary bike and light shooting.
"I know he's going to give us what he can," Carlisle said. "That's good enough for me. I don't spend a lot of time worrying about it or situations where he's unavailable. We've had other guys that have been able to step forward."
Carlisle also was asked about the notion, voiced by Dirk Nowitzki, that the Mavericks need a healthy Howard to have a chance in the series.
"I'm not going to sit here and think about reasons why we can't win the series," Carlisle said.
Field day for Nene: The inside scoring of Nene has provided the Nuggets with another dimension. The athletic, mobile 6-11 center has averaged 24.5 points while making 68 percent of his field goal attempts in the series.
Much of his production has come in transition and the pick-and-roll.
Center Erick Dampier said the Mavericks might have to leave the Nuggets' perimeter shooters to cover Nene.
"You're going to give up something, one or the other," Dampier said. "We have to get in there, close that off and force guys to make those 3-pointers. They're not going to make all of them."
Lesson for Nuggets: Coach George Karl made certain his team hasn't forgotten the lessons of the first round.
Denver won the first two at home against New Orleans, took a 16-point lead in Game 3, then lost to briefly let the Hornets back into the series.
"Tomorrow, you've got a lot of veteran guys who are very angry at the Denver Nuggets," Karl said Friday.
"And I think they're going to come out in a lot of ways to get back their territory, regain their confidence and regroup using the home-court."