Updated

The Los Angeles Galaxy have missed Omar Gonzalez this season and coach Bruce Arena made a move this week to compensate for the loss of the 2011 MLS Defender of the Year.

Gonzalez tore his ACL in January while on loan with Germany side Nurnberg, and the Galaxy have looked shaky on defense with three losses through four matches this season.

With L.A. last in the Western Conference on just three points, Arena acquired Brazilian defender David Junior Lopes from Chivas USA this week for midfielder Paolo Cardozo.

Although Lopes had not played for Chivas USA this season - he appeared in just eight games last season - Arena believed the newly-acquired center back could step in against the Portland Timbers on Saturday at The Home Depot Center.

"He's an interesting player," Arena said, "I think he'll be able to help us. We'll see how he feels ... and we'll make a decision obviously in the next day as to what kind of role he might play."

Obviously Lopes had an easier adjustment as he moves from Chivas to L.A. - two teams that share the same stadium in California - but slotting into a new team could still be a challenge.

"[I was] a bit surprised because I haven't played a whole lot over there and now I'm here with the Galaxy, who are a big club, and I have to show a lot to play here," Lopes said on the league's website.

The Galaxy (1-3-0) have allowed eight goals through four matches, fewer than only the expansion Montreal Impact and winless - and pointless - Toronto FC.

"It's time now to show as a team and individuals the character we've got and that we've shown the last few years," L.A. star David Beckham told the club's website. "So far this season we haven't seen that."

Whether Lopes is asked to start right away or not, L.A. needs to start winning soon. Real Salt Lake is already 12 points away at the top of the West, and the Utah side shows no signs of slowing down.

Portland (1-3-1) sits just one point ahead of L.A. in the Western Conference, and has to believe it can escape with at least a point this weekend.

Considering the Timbers are on a three-game losing skid, the last two at home, a win at L.A. would be the perfect remedy for their early-season woes.

"We're really motivated for this matchup," Timbers goalie Troy Perkins said on the MLS website. "There's an edge, for one. Guys are working a lot harder, a lot more is being said by the coaching staff about what is expected."

Timbers coach John Spencer knows the pressure is always on when results aren't produced, but he remained confident this week the squad has the talent to turn things around.

"The game's always easy and always simple for everyone watching and everybody that's coaching when you're winning," Spencer said. "Everybody is a genius when you're losing. Everybody is full of opinions of what you should do and what you shouldn't do. But we know what we've got in this squad. We know the quality we've got here."