SANTA CLARA -- The 49ers' NFC West title defense just got more intriguing thanks to Monday's quarterback carousel.
Shortly before the 49ers acquired Colt McCoy from the Cleveland Browns, the Seattle Seahawks traded away their only backup quarterback, Matt Flynn, to the Raiders.
The Arizona Cardinals joined the quarterback-transaction fray as they looked to upgrade from last season's last-place finish in the NFC West. They released last season's opening-day starter, John Skelton, and worked on acquiring Carson Palmer from the Raiders.
Palmer's potential move might not be as impactful as the Seahawks' loss of Flynn, at least regarding the 49ers' cause.
The Seahawks have built themselves into the 49ers' staunchest contender in the NFC West. Meanwhile, new Cardinals coach Bruce Arians is inheriting a 5-11 team that allowed a league-high 58 sacks last season.
What will the Seahawks do for a backup to Russell Wilson, who blossomed into a rookie sensation with the Seahawks last season? Tyler Thigpen and Matt Leinart are under consideration, according to ESPN.
Wilson started all 18 games last season, including their two playoff appearances. The Seahawks, who are becoming a more-rounded team, still are counting on Wilson's durability. He passed for 3,118 yards (26 touchdowns, 10 interceptions) and ran for 489 yards (four TDs, 33 sacks) as a rookie starter.
The 49ers are banking on Colin Kaepernick more than ever as their starter after trading Alex Smith to the Kansas City Chiefs. McCoy's acquisition will add depth and also provide competition for Scott Tolzien, who's been groomed just as long as Kaepernick (since 2011) in the complex and multidimensional scheme run by coach Jim Harbaugh and coordinator Greg Roman.
The 49ers might further add to their quarterback stable through this month's draft, in which they still have 13 picks, including seven in the first four rounds. Their more pressing needs, however, exist at free safety, defensive line, cornerback, tight end and offensive tackle.
By dealing Flynn to the Raiders, the Seahawks reportedly are getting a fifth-round draft pick next year and a conditional pick in 2015, which is a far cry from the 49ers' bounty for Smith (second-round pick in 2013, conditional third-round choice in 2014). Smith, however, is way more experienced with 75 career starts, as opposed to Flynn's two.
Seattle also is getting $3.25 million in 2013 salary-cap relief for Flynn, according to ESPN.com. Flynn's most extensive action for the Seahawks came when he replaced Wilson on the Seahawks' final series of a Dec. 23 rout of the 49ers, resulting in three kneel-downs to kill the final 1:40.
While the Seahawks and 49ers have upped the stakes in their rivalry, the Cardinals are trying to escape the NFC West dungeon.
Palmer went 8-16 as the Raiders' starting quarterback. He passed for more than 4,000 yards last season during their 4-12 run, and his interception percentage of 2.5 per attempt was his lowest since 2005 and 2006, when he drew his only Pro Bowl berths with the Cincinnati Bengals.
As for the St. Louis Rams, their biggest offseason move was to sign offensive tackle Jake Long in hopes he can protect Sam Bradford, who is backed up by Kellen Clemens and Austin Davis.