OAKLAND, Calif. -- Another injury has suddenly sidelined Dallas Mavericks superstar forward Dirk Nowitzki.Less than an hour before Thursday's game against Golden State, the Mavs announced that Nowitzki wasn't going to play against the Warriors because of a strained right adductor. Also, the Mavs, who play at Phoenix at 8 tonight, did not give a timetable on when they expect Nowitzki to play again.It is not known when Nowitzki's injury occurred, especially because after Thursday morning's shoot-around he said he had made a lot of progress following the arthroscopic right knee surgery he underwent on Oct. 19.Elton Brand started at power forward in Nowitzki's place against the Warriors.But it's clear the Mavs will need effort from a lot of players in order to make up for Nowitzki's absence.Nowitzki missed the first 27 games of the season while recovering from knee surgery and wasn't completely 100 percent before this latest injury occurred. It is not known if the two injuries are related.But the Mavs' chances of reaching the playoffs for the 13th straight season will be slim if Nowitzki is out for an extended period of time."Everybody's got to step up because everybody knows that Dirk is a big part of our team, so when he's not playing you can feel the difference," point guard Rodrigue Beaubois said. "So we've just got to make sure we all bring everything we've got and play together."Nowitzki is the only 7-footer on the Mavs' roster besides Chris Kaman. But neither played against the Warriors, because Kaman flew home after Thursday's shoot-around and is out indefinitely after suffering a concussion in Monday's practice.That leaves Brandan Wright and James -- at 6-10 each -- as the tallest players on the Mavs' active roster."We're still an inch or two off, but I think we can get the job done," James said of he and Wright. "Me and B-Wright can both jump a little bit higher than both of those guys, so I think it kind of makes up for that inch."In 18 games since his knee surgery, Nowitzki is averaging 14.8 points and 5.5 rebounds in 29.9 minutes per game."We want him to play with us, but if he can't that really means he's hurt because he's a warrior," Beaubois said. "We want him to play with us, but if he can't then we'll wait until he gets healthy."Assists are trendingCoach Rick Carlisle likes the way his team has improved in its ability to create assists."It's been trending really the entire year, particularly in the last two or three weeks," Carlisle said. "We've got to continue with that and we've got to shore up some other areas."The Mavs collected 31 assists in Tuesday's 106-104 loss to the Portland Trail Blazers and are 12th in the NBA with 22.5 assists per game. Carlisle credits the new players getting accustomed to one another with the progress the Mavs have made in that department."I just think that as the year has gone on I've newer guys have gotten more integrated in what we're doing, the culture of trusting the pass," Carlisle said. "It's been a good progression."