Once quarterback Matt Cassel was placed on injured reserve three games into the year, the Vikings season was mainly about the growth of rookie quarterback Teddy Bridgewater and how he adjusted to the NFL.

He jumped into the mix faster than anticipated with Cassel's foot injury, but Vikings head coach Mike Zimmer is saying that Bridgewater's on-the-job training will benefit the quarterback, the offense and the organization down the road.

"I really think you learn best from playing," Zimmer said. "That's what I believe, and I'm glad that he's playing. …What I was nervous about at the beginning of the year was I didn't want to get him beat up, I didn't want to get him gun-shy, I didn't want to get him a bunch of bad outings where he didn't have the confidence and that attitude that he was going to do the things that he's doing."

Another concern Zimmer had with Bridgewater making his first start four games into his career was his health. The Vikings have gradually lost three starting offensive linemen and shuffled around at every position except left tackle Matt Kalil, who has been inconsistent, and center John Sullivan.

Bridgewater is tied with Steelers quarterback Ben Roethlisberger for the eighth most sacks taken in the NFL this season with 32. Zimmer believes the protection has improved as of late with Bridgewater sacked a combined six times against a good Jets and Lions defensive line.

"I'm glad that we're keeping him upright," Zimmer said. "You can think back, and I know it's just my belief, you think back on some of the quarterbacks that have had to play as rookies or been playing as rookies and got the heck beat out of them and they haven't made it. So that was the most important thing to me to start this season is that we take care of him and when it's time, it's time."

It's evident Bridgewater has made gradual strides over the course of this season, with many learning experiences along the way in 10 career starts. The latest occurred in a 16-14 loss to the Lions at Ford Field on Sunday, when the Vikings offense couldn't score in the second half and missed out on two opportunities in the final four minutes to take the lead.

"I think in the long run his playing and going through all these experiences and getting a chance to play against Green Bay, Chicago and Detroit will be a big factor for us in the future because he's been through these things now," Zimmer said. "It's not new. If he wasn't playing, that fourth quarter[against the Lions], the things that happened in the ballgame, maybe next year we're in the same boat and he's learning from it then as opposed to learning from it now."