Dwight Howard will visit American Airlines Center for the second time this season Wednesday night. Are the Mavericks still disappointed that he isn’t playing there on a regular basis? After more than half a season has elapsed, Howard’s time with the Houston Rockets has been something less than earthshaking. If you looked at the NBA standings on Tuesday, the Rockets were three games ahead of the Mavericks in the Western Conference. So they aren’t exactly lapping the field. That doesn’t mean Howard hasn’t worked out nicely for the team on the south end of Interstate 45. They won the free-agent derby for the best center in the league last summer and are thrilled to have that firepower. And yet, the Mavericks are 2-1 against the Rockets this season with a chance to win the season series against a team ahead of them in the standings, which would be a significant accomplishment for a team that has done its share of wobbling so far this season. “Yeah, we’ve been struggling a little bit against teams that are above us, or even the Eastern Conference teams that have a better record,” Dirk Nowitzki said Tuesday. “I think we have a losing record against those teams, so any game that we can win against those teams is big, is a confidence builder. “If you look at the race, you can’t really afford to lose any games. It’d be another huge win for us. You’d get the tie-break. They’re only a couple of games ahead of us, so it’s a big game.” The Mavericks have moved on after their swings and misses in free agency the last two summers. They saw Deron Williams last week and were reminded why he’s one of the league’s top point guards as Brooklyn got the win. Now it’s Howard for the last time this season, assuming there’s no playoff series between the Mavericks and Rockets. And don’t think for a second that the Mavericks are regretting their decisions to keep salary-cap flexibility above everything else. They still envision a day when Nowitzki is their second-best player. “That’s the hope and the plan,” president of basketball operations Donnie Nelson said. “I think we’ve done it kind of by committee. Monta’s really provided us a really cool punch and someone who on any given night can win a game.