Wahl now wears Montreal’s blue, not Rave Green.Being carted off the practice field is never a good thing, and the fears of Sounders FC fans were realized two days ago: forward David Estrada, the team’s leading scorer with five goals, would be sidelined from eight to 12 weeks with a fractured fifth metatarsal in his left foot, suffered in practice the previous day.It’s just the latest in a litany of injuries and suspensions that have plagued the Sounders all season, preventing the club from fielding their best 11. It comes as the schedule resumes–after a three-week break from league play–with tomorrow’s match in Montreal against the expansion Impact (4:30 p.m., KONG-TV) as Seattle puts a 10-match road unbeaten streak (7-0-3) on the line.The Sounders, third in the Western Conference with 24 points, trailing Real Salt Lake (29) and San Jose (27), could use a win–their most recent MLS victory was more than a month ago, May 9 at FC Dallas; they’ve gone 0-2-2 since.Emotions will be high in Montreal as the Impact, who played their first three months at cavernous Olympic Stadium–where they set an MLS record last month, drawing nearly 61,000 for a match against the L.A. Galaxy–move into the renovated Stade Saputo, a 20,000-seat, soccer-only venue, also on the grounds of the 1976 Summer Olympics. The sport’s professional history in Quebec goes back more than 40 years, to the North American Soccer League’s Montreal Olympique (1971-73) and Manic (1981-83). In addition to Estrada, the only Seattle player to see time in every match this season, the Sounders will be without midfielder Ozzie Alonso, who’s serving the second of a two-match suspension for a reckless challenge late in last month’s 2-0 loss to Columbus, as well as three injured defenders–left back Leo Gonzalez (quad), center back Patrick Ianni (lower back), and right back Adam Johansson (hamstring). Michael Gspurning, who started the first six matches in goal, will miss his seventh consecutive contest with an injured hip.Rookie Bryan Meredith, who’s given up five goals in his past three MLS matches, will make his seventh start in Gspurning’s stead. The injuries to the trio of defenders means Seattle will go with a back four of Marc Burch, Jhon Kennedy Hurtado, Jeff Parke, and Zach Scott for the fourth straight contest (including two U.S. Open Cup matches over the past two weeks), leaving Sigi Schmid with few good options if one of the four can’t go the full 90. English rookie Andy Rose, who subbed for Alonso against Dallas and Chivas USA, is a good bet to start in the Cuban star’s place, especially after scoring his first goal in a Sounders uniform two weeks ago and adding another last week. Estrada’s injury means more time for veteran Eddie Johnson, partnering with Fredy Montero up front, and an opportunity for second-year forward Sammy Ochoa, who had seen little action in the first three months but played well in both U.S. Open Cup matches, starting both and scoring two second-half goals against Atlanta that showcased his ability to finish.The Impact, Major League Soccer’s newest team, are in many ways the Sounders’ mirror image. They’ve gone 3-7-3, with eight of their matches on the road; Seattle is 7-3-3, playing eight times at home. Montreal is 1-4-1 against the Western Conference; Seattle is 4-1-1 vs. the East. The Sounders, for all their offensive firepower, have outscored Montreal just 16-15, but the contrast on defense is glaring: the Impact have surrendered 21 goals, tied for the league’s worst with one-win Toronto FC, while stingy Seattle, which goes seven deep when everyone is healthy, has yielded just nine. Montreal would have given up several more goals if not for veteran keeper Donovan Ricketts, a longtime fixture on the Jamaican National Team who has played every minute of every match this season.Montreal has been tough at home, giving up only a goal per match while beating Toronto and Portland and drawing with Chicago and L.A; the loss was 2-1 to New York. The Impact have demonstrated their potential twice on the road, with a stunning 2-0 victory at Sporting Kansas City and hard-fought 1-1 draw at D.C. United. The team is on a two-match skid, on the heels of a four-match unbeaten streak that bridged April and May. Sounders fans will see four familiar faces in Montreal’s blue uniforms. Speedy Gambian forward/midfielder Sanna Nyassi–who has played in 12 matches, starting nine, scoring one goal and setting up another–played for Seattle in 2009 and 2010. Defender Tyson Wahl, a Sounder for the team’s first three seasons, has made 10 starts for the Impact. Midfielder Lamar Neagle, a fan favorite from Federal Way who scored five goals last year as a rookie, then was dealt to Montreal in February with Michael Fucito (since traded to Portland) for the rights to Johnson, has played in 11 matches, starting five, with two assists. Forward Miguel Montano, who saw limited action in Seattle the past two seasons, played well last month against the Red Bulls in his only start.Canadian Patrice Bernier and 21-year-old Brazilian Felipe make things happen in center midfield, with captain Davy Arnaud, a longtime starter in Kansas City, and Justin Mapp holding the line on the right and left respectively. Bosnian backup Sinisa Ubiparipovic has been effective when he’s played. The Impact’s main scoring threat is 36-year-old forward Bernardo Corradi, who boasts more than 250 appearances in Italy’s Serie A for Chievo, Lazio, and Udinese and is a former member of the Italian National Team. He’s scored four times this season despite putting only seven shots on goal. This match could mark the debut of another international, veteran forward Marco Di Vaio, 35, who spent the past four seasons with Serie A’s Bologna, capping a long Italian career that saw him play in nearly 350 matches for six clubs. Two Montreal defenders, Matteo Ferrari and Colombian Nelson Rivas, who may not play due to a sprained knee, also have experience in Italy’s top league. Tomorrow’s match kicks off a brutal stretch for the Sounders, who play four times in 11 days, returning home to face Sporting KC on Wednesday, then going on the road for a Cascadia Cup clash at Portland next Sunday, and continuing down the coast for a U.S. Open Cup quarterfinal against San Jose two days later in San Francisco.