If you're a Vikings fan, you should be happy that linebacker Chad Greenway came out of nowhere to intercept Teddy Bridgewater during an 11-on-11 red zone drill during Saturday night's practice in front of a packed house at Blakeslee Stadium.

Why?

Because it was tremendous reinforcement for the rookie that what used to be open at Louisville isn't open in the NFL.

Running the first-team offense during Saturday night's red-zone segment of practice, Bridgewater had the ball inside the five-yard line when he dropped back to pass. Receiver Greg Jennings appeared to pop open for a split second. Greenway read the play perfectly, anticipated where the rook would go with the ball, got a great jump and closed the window with the interception.

"That's a situation where [offensive coordinator Norv] Turner always tells me that I have to be quicker with my decision-making," Bridgewater said. "In that situation, I have to understand the situation. We have points on the board [in a field goal attempt]. I have to get my head around faster. Everything happens faster in the red zone. I have to understand the situation. [Sunday], I'll be able to look at the film and learn from my mistakes."

Bridgewater wouldn't say whether he saw Greenway, but indicated the he did see him and thought he could zip the ball past him.

"Chad made a great play," Bridgewater said. "Still, my primary progression wasn't there. I should have gotten off of it. I saw Greg pop wide open and I thought I could squeeze it in there. But down in the red zone, if you have points, there's no need to force throws."

We have to remember that Bridgewater is indeed a rookie. He got off to a great start in camp, but has leveled off with four interceptions the past two days as more of the offensive and defensive packages have been installed.

Bridgewater was asked how long it will take him to get a feel for what's open and what isn't open at this level.

"I'll learn that in no time," he said. "It's all about experience and repetition. That's something I can learn from tonight, that open in the National Football League is totally different than college football. Open in the National Football League is a guy not even out of his break yet when he's running his route. College guys are wide open even after their break."

CASSEL CONFIDENT HE'S THE MAN: Cassel threw two interceptions Saturday night and one on Friday. But he said he's not concerned because two of the interceptions were a matter of quarterback and receiver getting in sync in a new offense. (This, after all, is why these guys practice). The other interception was the defensive play of camp by far. Cornerback Xavier Rhodes made a diving, fully-extended catch with an awkward roll at the end to rob a deep ball intended for Jarius Wright.

Cassel and the first-team offense looked sluggish and did not score in the two-minute segment. Bridgewater and the second-team offense looked crisper, ending that segment with a Bridgewater-to-Rodney Smith touchdown pass. Cassel and the first unit threw two incompletions into the end zone as the clock expired.

Overall, Cassel said he feel a lot more comfortable in Turner's offense.

"I feel great, I honestly do," he said. "I feel like I'm picking up the verbiage. The biggest thing early on was just getting in and out of the huddle and just being able to say the plays. Now that I'm able to do that, I think I have more confidence going to the line of scrimmage and being able to execute those plays."

Cassel's other interception Saturday went to cornerback Marcus Sherels, who was working with the first team. Sherels got good position on Cordarrelle Patterson and made the sure-handed pick.

Asked if that was a case of Patterson running one route and Cassel thinking it should have been another, Cassel said, "Right. Exactly. It's a go route. He went inside. I'm thinking he's going to stack him. That's just one of the things that happens in camp. Issues come up and you correct the mistakes. And as you come back out the next time and run that go route again he's on the same page and running that go route where I think he's going to and vice versa."

Cassel also said Bridgewater getting the first-team red zone reps was par for the course and doesn't indicate that the rookie is gaining ground on him.

"That's normally what happened everywhere I've been," Cassel said. "The No. 2 guy, you have to get him ready to play at any point. The fact of the matter is he's going to get reps with the one's and this is the time of year to do it. it's also a situation where they're preaching competition. I think competition makes all of us better, including myself. I embrace that part of it."

The Vikings have today off and return to practice on Monday. It will be worth watching Bridgewater to see if he learned a thing or two from Greenway on Saturday night.