RENTON, Wash. -- No matter how you look at it, Sunday was not a good day for the Seattle Seahawks.

The downer started when news broke that cornerback Walter Thurmond faces a four-game suspension for non-PED substance abuse. It’s a player Seattle can ill-afford to lose since Thurmond was starting for Brandon Browner, who is out with a severe groin pull.

Thurmond sent out this tweet on Sunday:

I'm disappointed in myself for letting my teammates and family down. — walter thurmond III (@WaltThurm3) November 24, 2013

The results of the Sunday games also didn’t do the Seahawks any favors. NFC West teams Arizona and St. Louis both won. The Rams (5-6) aren’t much of a threat to 10-1 Seattle, but St. Louis had an impressive 42-21 win over the Chicago Bears Sunday. St. Louis ends the regular season at Seattle.

The Cardinals were one of the big surprises of the day with a 40-11 victory over the Indianapolis Colts. Arizona is 7-4 and has won four consecutive games since the loss at home to Seattle. The Cardinals play the Seahawks at CenturyLink Field on Dec. 22.

San Francisco will improve to 7-4 if the 49ers win Monday night in Washington. The Seahawks play the 49ers at Candlestick Park on Dec. 8.

And the comeback victory by Carolina (20-16 at Miami) Sunday leaves the Panthers in the hunt for home-field advantage in the NFC at 8-3. It makes a win over the New Orleans Saints next Monday night even more imperative for the Seahawks.

A loss would leave both Seattle and New Orleans 10-2, only one game ahead of Carolina, the give the Saints the tiebreaker over Seattle. The Panthers and the Saints still have two games against each other.

The Seahawks still have a three-game lead in the NFC West and continue to hold down the top spot in the NFC. It all still can turn out in Seattle’s favor, but Sunday wasn’t helpful.

And there was one tiny bit of good news Sunday. Denver's 34-31 overtime loss to New England could move the Seahawks to the top spot in the ESPN.com power ranking.