The third-seeded Sounders will visit the Monterrey area to meet sixth-seeded Tigres in the first match of their aggregate-score series. The second game will be played at CenturyLink Field.
Other pairings will be No. 1 Monterrey vs. No. 8 Xelaju; No. 4 Los Angeles vs. No. 5 Herediano; and No. 2 Santos Laguna vs. No. 7 Houston.
"Playing a team from Mexico, at least we're away first and home second, which is a plus, and we're avoiding for sure the big two that have done very well in the last couple years in this competition -- Monterrey especially," Sounders coach Sigi Schmid said yesterday before the final pairings were set. "All we can control is our own destiny, and then the rest is up to them."
If the Sounders advance, they would face the Santos-Houston winner in the semifinals.