The USA international, who scored in the first leg in Seattle, and his Santos teammates edged the Sounders 2-1 on aggregate despite a 1-1 draw in Mexico and he was full of admiration for Sigi Schmid and his men following the contest.
"I've said from the first day when we knew we were going to play Seattle, that they're a dangerous team," Gomez told MLSsoccer.com.
"They've got players that can hurt you on a break. They're good enough to be here [and] that's why they're here.
"We respect them."
He added: "Credit to them, they made it difficult. They pressed, they got their goal, they definitely took it to us in the second half. I said it before, you give a team like Seattle confidence and they're going to cause problems, and that was the case."