Kasey Keller knew exactly when all the good will from spending his college career in Portland was gone.

When Keller attended a Portland Trail Blazers game last January he was able to get courtside tickets. As the video board at the Rose Garden panned the arena showing those in attendance, the camera stopped on Keller.

In the past, his picture might have elicited cheers or at least a polite ovation for the former University of Portland star and U.S. national team goalkeeper.

This time, with Keller playing for the Seattle Sounders and the Portland Timbers just months from joining Major League Soccer, the reaction was a little more unfriendly: a tidal wave of boos.

"That was pretty cool. I got a good laugh out of it," Keller said. "... That just shows you the state of the rivalry and the state of the game here in the Northwest and hopefully that just continues to grow and grow and grow."

Keller and the Sounders will enter the hornet's nest of JELD-WEN Field on Sunday afternoon when they face the rival Timbers in the first MLS match between the two sides played in Portland. And for Keller, it's likely the last time he'll play professionally in the city where he first made his mark as a college star playing for Clive Charles at Portland before becoming the first American goalkeeper to play successfully in Europe.

Just don't expect any fawning by the Timbers' Army, even if Portland coach John Spencer called the 41-year-old Keller "an American goalkeeping legend" on Friday.

"Although I do hope he has a stinker this weekend," Spencer joked.

While there is a healthy respect between the two organizations running the Timbers and Sounders, there's still plenty of acrimony. Seattle became the darling of the MLS during its successful first two seasons, becoming the benchmark by which all future MLS expansion franchises would be judged.

But as Seattle got the attention, Portland made sure everyone remembered it was the first city to gain the moniker "Soccer City USA" with a strategically placed billboard just a couple of miles south of the Sounders home field. It was just the start for the Timbers, who have sold out every game at their renovated stadium in downtown Portland and seem to have matched the fervor Seattle created in its debut season.

Not much got settled on a washed out Saturday night in Seattle in May when the Sounders and Timbers played to a 1-1 tie before 36,000 rain-drenched fans, other than the supporters groups from both teams successfully getting in and out of the stadium without problems developing between the two sides. There were also some words tossed back and forth between Spencer and Seattle coach Sigi Schmid. Both said this week that the verbal jabs were not meant to be personal in any way.

Now comes the return meeting.

"I have a lot of respect for John (Spencer) as a coach. I know we said a lot of things back and forth but I think he is a really good coach," Schmid said. "I thought he was a really good player and I've always liked him and I enjoy the banter as well."

Keller has returned to play in Portland twice since coming back to the U.S. and joining the Sounders, but both of those matches were in U.S. Open Cup play. Seattle beat the then-USL Timbers 2-1 in 2009 and knocked off the Timbers on penalty kicks a year ago after the two sides played to a 1-1 draw in regulation.

But that was before the Timbers joined MLS and Keller says the atmosphere for those Open Cup matches won't compare with what he'll experience on Sunday.

"I'm excited to see the improvements to the stadium. What it's going to feel like, it's going to feel like it did for Costa Rica when we played there with the national team where it was a great, loud, raucous crowd," Keller said in reference to the 1997 World Cup qualifier played in Portland. "Unfortunately they'll be rooting against me instead of with me."

Seattle enters the rivalry showdown on a roll, having gone seven straight matches without a loss. Their 32 points is the third-highest total in the league, behind only Los Angeles and FC Dallas.

Meanwhile, the Timbers are slogging through the struggles most expansion franchises face. Portland is just 0-5-1 over its last six matches since beating Columbus on May 21.

"These kind of games, form goes out the window. It doesn't matter that we've been on the run we're on and they've been struggling. It doesn't mean a thing," Keller said. "This is a game where both teams are going to have to roll up their sleeves and a game where somebody is going to have to capitalize on somebody's mistake or who does something special to change things. These are tough games for players."