The Seattle Sounders on Tuesday night face not only the unenviable task of trying to win a CONCACAF Champions League semifinal game on the road, but they must accomplish the feat against some formidable opposition in Mexico as well. Santos Laguna, which is trying to book a spot in the final for the second consecutive year, brings in a one-goal advantage after winning the first leg of the aggregate semifinal series in Seattle, 1-0, last week.