It's hard to know what was going on behind the scenes with Matt Cassel and the Vikings that led to the QB being traded last week to Buffalo. Maybe with Teddy Bridgewater firmly established as the No. 1 QB, Cassel asked to be sent somewhere that he could compete for a job. Maybe the Vikings decided paying Cassel wasn't worth it. Or maybe Buffalo came in with a trade offer the Vikings deemed too good to refuse.

Whatever led to the trade, it has now led to this: uncertainty at the backup QB spot, which in recent years has become a pretty important spot in the NFL.

Some Vikings fans assumed the move meant Minnesota would go after and land former Browns QB Brian Hoyer because of his relationship with offensive coordinator Norv Turner, but Hoyer is good enough that he, too, is looking for a chance to start. That has led to reports that he is down to picking between either the Jets or the Texans.

While there are still competent backup QBs on the market — there is reportedly mutual interest between Minnesota and veteran Shaun Hill, who did a tour of duty here a decade ago — the Vikings gave up a sure thing in Cassel.

Maybe in a season during which the Vikings don't figure to be quite ready to contend, that's not a terrible gamble since a Bridgewater injury would put a huge damper on things regardless of who the backup QB is. This isn't 1998 (when Brad Johnson was the starter but Randall Cunningham replaced him after he was injured and led a 15-1 season) or 1999 when Cunningham was replaced by Jeff George, who led a playoff surge.

But in the modern NFL, giving up a capable backup for an unknown is a gamble nonetheless.