Ozzie Alonso will have his hands full with Donovan … and vice versa.Sounders FC can take another step tonight in the quest to join Major League Soccer’s elite with a franchise first: beating the Los Angeles Galaxy on home turf.The reigning MLS champs have had Seattle’s number as long as the Sounders have been around, winning three of six regular-season matches (with two draws) and bouncing the Sounders in the opening round of the 2010 playoffs, winning 1-0 and 2-1. L.A. has outscored Seattle 6-0 in its past three matches here.The Sounders can flip that script before 38,000-plus howling fans at CenturyLink Field (7 p.m., KONG-TV).The Galaxy–and the rest of the league–got a jolt yesterday when it was revealed that starting goalkeeper Josh Saunders, who had missed last Saturday’s 1-1 draw with FC Dallas for what were described as personal reasons, has left the team indefinitely to enter Major League Soccer’s substance abuse and behavioral health program. Backup keeper Bill Gaudette will make his second consecutive start for L.A. after going without an MLS appearance for nearly six years. Gaudette’s last league victory came in September 2006 for Columbus, then coached by current Sounders head man Sigi Schmid.L.A.’s strength is its offense, and midfielder Landon Donovan, the Galaxy’s all-time leading scorer and a MLS All-Star for 11 consecutive years, is one of a handful of players in this league who can win a match single-handedly. He may have to, because Donovan won’t have his usual supporting cast. With L.A. in the midst of playing three matches in eight days and the fact that this one will be contested on FieldTurf, not grass, Galaxy coach Bruce Arena decided that neither English star David Beckham–who turns 37 today–nor veteran Irish forward Robbie Keane would make the trip north. That puts more pressure on striker Edson Buddle, back in L.A. after a year in Germany, and just two seasons removed from scoring 17 goals for the Galaxy. L.A. stumbled out of the gate this season, knocked out of the CONCACAF Champions League home-and-home quarterfinals by Toronto FC (meanwhile, the Sounders were going down to Santos Laguna) and dropping three of their first four league matches as the defense, the league’s best in 2011, was shredded for a dozen goals in the six contests.The key to the Galaxy’s less-than-stellar start was the absence of Omar Gonzalez, 2011’s MLS Defender of the Year, in central defense. Gonzalez is expected to miss most of the season after tearing the ACL in his left knee in January. The Galaxy have righted the ship since acquiring Brazilian center back David Junior Lopes from Chivas USA last month, with two wins and a draw in their past three matches. There was an unlikely hero against FC Dallas, as Pat Noonan, who spent the previous two seasons in Seattle, scored in the second minute of stoppage time after coming on as a late substitute. Noonan’s first goal in an L.A. uniform was also his first since he scored as a Sounder in June 2010.By contrast, Seattle’s central defense, led by Jeff Parke and Patrick Ianni, has been consistently solid, and will only improve with the return of Jhon Kennedy Hurtado, who has finally recovered from a pelvic injury he suffered a month ago and went all the way in Saturday’s 2-1 win at Chicago. Michael Gspurning (who celebrates his 31st birthday today) was eyeing his fourth consecutive clean sheet before the Fire’s Marco Pappa curled in a corner kick in the 89th minute, ending the Seattle keeper’s shutout steak at 337 minutes. The defense has given up three goals, tied for the league low, just one in the run of play.The Sounders, dogged by injuries through their first six matches, aren’t quite yet back to full health. Midfield catalyst Mauro Rosales, who returned on the right side against the Fire after being out a month with a sprained right knee, took a nasty kick to his right ankle and was forced to leave early in the second half. On the left side, Alvaro Fernandez hopes to get back on the pitch after missing the past two matches with a strained right quadriceps. If he can’t go, expect David Estrada to start in his place.The closest the Sounders have come to winning at home against L.A. was a 1-1 draw in their first-ever match against the Galaxy in May 2009. Curiously, Seattle has won both of its U.S. Open Cup contests against the Galaxy, both played at Starfire in Tukwila. If the Sounders can’t get it done tonight, they’ll have at least two more cracks at the Galaxy this year: a rematch at the Clink on August 5 and the final match of the regular season, October 28 in Carson, Calif.