Dallas looks to end a three-game skid by earning its fifth straight victory over visiting Washington on Wednesday night.
The Mavericks (4-4) won four of their first five games without Dirk Nowitzki, but they've lost their last three after falling 90-82 at home to Minnesota on Monday.
Darren Collison scored a game-high 21 points for Dallas, which shot a season-worst 36.3 percent.
"For one thing, on the offensive end, we're not making the shots that we normally make the last few games, and the result of all that is we're being too stagnant," Collison told the team's official website. "And then on the defensive end, we're just not buckled down and tied in like we need to be.
"We're not going to always win games shooting at a high percentage. Sometimes you're gonna have to win ugly games."
Coach Rick Carlisle was ejected after arguing a foul with roughly five minutes remaining Monday, and he wasn't pleased with what he saw before that.
"Our effort wasn't where it needed to be," Carlisle said. "I thought we tried hard in the second half and the results were still not good.''
It's been hard to criticize O.J. Mayo much in his first eight games with the Mavericks. He scored 18 points against Minnesota and is averaging 24.5 over his last six, but knows his new team has room for improvement.
"It's not the end of the world,'' Mayo said. "But at the same time, we have to get back to getting better.''
Shawn Marion will miss his fifth straight game Wednesday as he recovers from a left knee sprain, and Carlisle said there's a possibility he could alter his starting lineup to boost energy.
The most likely move would be replacing rookie Jae Crowder with Dahntay Jones.
"We've got to personalize our effort - individually and as a team - and right now, we've got to dig ourselves out of this losing streak," Carlisle said. "The way you do it is you start with a jump ball and you've got to dig in on every possession. Simple as that."
Washington (0-6) was more than lackluster during its 92-76 loss at Charlotte on Tuesday, shooting 29.8 percent - an NBA single-game low this season.
Trevor Ariza scored 19 points and was the only player in double figures for the Wizards. Rookie Bradley Beal finished with eight points and hit one of 11 shots from the field.
"We can't lose focus, and (Tuesday) we weren't focused,'' Beal said. "We came in lackadaisical, like we were 5-0 instead of 0-5. We didn't come in with the edge that we usually do.''
Washington, which started a franchise-worst 0-8 last season, has yet to play with former No. 1 overall pick John Wall (right knee) or Nene, who is recovering from a left foot injury.
Nevertheless, coach Randy Wittman has yet to make any excuses for a team he says needs to make better decisions on both ends of the court.
"When you stand around and watch a guy dribble and dribble and dribble and take a bad shot, it takes away that effect (on defense),'' Wittman said.
The Mavericks have won four straight meetings with Washington, though each has been decided by 10 points or fewer. The Wizards won 102-91 in Dallas on Oct. 27, 2009, for their only victory in the last seven matchups.