[MLS] In a 1-1 tie with Northwest foe Portland that kicked off a new era of hostilities between the former NASL and USL rivals, Seattle suffered another injury setback, this time to midfielder Brad Evans.

Shortly before the 2011 season started, Sounders coach Sigi Schmid put pressure on his team as well as himself when he declared that after two seasons in the league with him at the helm, the time was right to win MLS Cup.

But a run of player upheavals and injuries has the Sounders dipping deeper into their roster, and another starter came out of the game early in a 1-1 tie with the Timbers Saturday at Qwest Field. Midfielder Brad Evans, a vital component who usually plays centrally alongside Osvaldo Alonso, came off the field grimacing shortly before halftime, and eventually was diagnosed with a groin strain.

Already this year, Seattle has lost Designed Player Blaise Nkufo to a preseason impasse with Schmid over his role on the team, and early-season medical setbacks for Steve Zakuani (fractured ankle) and O’Brian White (surgery to remove a blood clot). Evans missed time last year with a left patellar tendon injury, and in 2009 suffered a concussion, knee injury, and ankle bruising in a collision with former FC Dallas goalkeeper Ray Burse.

Schmid already had revamped his lineup to face Portland when projected starter Erik Friberg sprained an ankle Friday morning and had to be scratched. His replacement, former USL Sounder Roger Levesque, played a part in the sequence that produced Alvaro Fernandez’s goal  in the 52nd minute. Levesque has a different skill set than Evans, but he, too, is a tireless, relentless worker.

All three players are midfield options for Schmid, if Evans – who missed last week’s game against Columbus with a quadriceps strain – is going to miss significant time. But the balance between attack and defense in Seattle’s system has relied in part on the two-way work of Alonso and Evans, and the long-term absence of Zakuani deprives Seattle of his ability to stretch the defense from the left flank. Friberg has perhaps the highest work rate of the alternatives, which also include Mauro Rosales.