HOUSTON -- There is a good reason the Dallas Mavericks were among the suitors for Josh Smith before his midseason signing with the Houston Rockets.

No, Smith's soft perimeter touch had nothing to do with it, never mind the renowned bricklayer knocking down a career-high-tying four 3-pointers to help Houston hold off the Mavs 99-94 on Wednesday night. It's because the Mavs need all the bench help they can get.

That reality has slapped the Mavs during their first four-game losing streak in two seasons.

A lot of things have gone wrong during this skid that has knocked Dallas down to seventh place in the Western Conference standings. Not much has gone right for the Mavs' reserves.

Dallas' bench has been outscored by double figures in each of the four losses. The Mavs' second unit is at a 76-point disadvantage during the streak.

It really got ugly against the Rockets, who had a 47-18 edge in bench points. Smith, whom the Mavs tried to recruit to replace Brandan Wright, had as many points as all Dallas reserves combined.

"Everybody's in a little bit of a rut," sixth man Devin Harris said after a scoreless outing for him, "but we're still searching for our identity and who we are."

The Rajon Rondo deal rocked the Mavs' rotation, and coach Rick Carlisle is still searching for solutions. So is the Dallas front office, which is optimistic about signing 36-year-old center Jermaine O'Neal before the All-Star break and will be aggressive in pursuit of proven veterans who receive buyouts if those opportunities present themselves.

The Mavs didn't give up any major assets to get Rondo, but Wright and gritty swingman Jae Crowder were both significant role players that Dallas has struggled to replace. The Mavs really miss Wright in particular.

Wright might not have been as impactful as previous Dallas sixth men, such as Jason Terry and Vince Carter -- who each just so happened to be on the opposing teams the past two nights -- but Wright was an impact player in his niche role.

It isn't just about the 8.8 points and 4.1 rebounds the high-flying Wright averaged as Tyson Chandler's backup this season. With the Mavs, Wright had a magnetic effect on opposing defenses due to the threat of him finishing above the rim, creating space for others to work. He had an especially good rapport with Harris, who hasn't been the same player since the trade.

With Wright on the floor this season, Harris scored 149 points in 310 efficient minutes, shooting 49.5 percent from the floor and 45.3 percent from 3-point range.

Without Wright on the floor, Harris has scored only 85 points in 321 minutes, shooting 33.8 percent from the floor and 34.3 percent from 3-point range.

That's a problem. Wright isn't walking through that door, at least not until the Mavs face the Phoenix Suns, where the Boston Celtics shipped him weeks after the Rondo deal.

"It's been tough," said Harris, who was 0-of-4 from the floor with three turnovers in only 13 minutes against the Rockets. "That's because we have a different team. We went from more of a pick-and-roll team -- getting guys at the rim, and if they take away the lob, we get wide-open 3s. We're not getting that anymore, so we've got to figure out different ways to be effective."

Even an excellent X's-and-O's mind like Carlisle struggles to compensate for major personnel issues.

Harris and fellow guard J.J. Barea have been the only constants off the Mavs' bench since the trade. And both of their production has slipped significantly as the Mavs have gone a mediocre 11-9 in that time.

"We've got to keep J.J. and Devin aggressive," Dirk Nowitzki said. "Keep getting them in the lane. They're both big playmakers for us."

The rest of the Mavs' bench rotation is about as predictable as the Texas weather.

Rookie Dwight Powell has had some promising moments, but it's far from ideal to rely on a rookie second-round pick who was a trade throw-in. But he's better than Greg Smith, not to damn with faint praise while waiting.

Al-Farouq Aminu was the only reserve to play well against the Rockets, recording 10 points, seven rebounds and six blocks in 29 minutes, but there's a reason he has gotten a lot of recent DNP-CDs. Just like there's a reason that Carlisle doesn't call on Charlie Villanueva or Richard Jefferson some nights.

"We've just got to figure it out," said Carlisle, who will keep tweaking the rotation. "There's no one answer, but we've got to keep up the collective fight."

The fights the past four games have left the Mavs' bench bloodied and beaten.