This is a blog about Stanford tight end Coby Fleener, but first, some context.

According to Matt Maiocco, Dashon Goldson is the Niners’ top candidate for the franchise tag. Franchising Goldson would cost the Niners $6.2 million in 2012, while it would cost them $10.6 million to franchise their other top free agent, Carlos Rogers.

So, Goldson most likely will be a Niner next season. But, will Rogers?

He wants a four year contract, but he said he’d take less money to sign with San Francisco. How much money would the Niners be comfortable giving to the 30 year old?

Maiocco says “the team believes (Chris Culliver) will be ready to start next year as a second-year player.” If that’s true, it doesn’t seem like the Niners feel desperate to re-sign their Pro Bowl corner.

If they let him walk, how will that affect their offseason?

First, they’ll probably have cap space to seriously bid for a big-bodied, free agent wide receiver – their biggest need by far. If they want the Saints’ Marques Colston, who is 28 years old and 6’5”, the Niners could potentially outbid and weaken their rival.

They’d also have to get another cornerback, probably in the draft but not necessarily in the first round. Teams usually expect and count on first rounders becoming starters in their first season. But, if Maiocco is correct that the Niners see Culliver and Tarell Brown as starter-caliber corners for next season, then Trent Baalke can draft a corner to develop in the second round, like Josh Norman from Coastal Carolina.

Here’s where Coby Fleener comes in. No matter what happens with Carlos Rogers, the Niners should draft Fleener in the first round.

But the Niners already have Vernon Davis and Delanie walker, you say. They don’t need another tight end.

What the Niners need is to improve their offense, especially on third downs and in the red zone.

Fleener would do that.

He’s 6’6”, he’s fast, and he can play tight end or wide receiver. He’s bigger and faster than any wide receiver who likely would be available at the 30^th pick of the first round.

Plus, he’s a much better receiver than Walker, the Niners current No. 2 tight end, who is short for the position, plus he drops passes.

Fleener is not as good of a blocker as Walker or Davis. But the Niners don’t need more blocking. They need more getting open and more catching. Fleener is known for both those things.

According to the Associated Press’ Antonio Gonzalez, who covered Stanford Football this season, the Cardinal players called Fleener “deceivingly fast,” and “the second fastest player on the team.”

Gonzalez says Fleener ran past linebackers easily – he even blew by safeties. So, by the end of his college career opposing defenses covered him with cornerbacks.

Fleener stretches the field just like Vernon Davis. If the Niners have both guys, neither one could be double teamed.

Imagine this shotgun formation on third down and long: Fleener and Davis at tight end, Colston at split end, Joshua Morgan at flanker and Michael Crabtree in the slot. Alex Smith could easily find good one-on-one matchups with that personnel.

If the Niners draft Fleener, they’ll have the best tight end corps in the NFL – better than the Patriots’ group with Rob Gronkowski and Aaron Hernandez.

If the Niners also sign Colston, they’ll be a good third down and red zone offense. They’d have too much talent not to be.

“Good” is a big improvement from “dreadful,” which is what the Niners offense was on third downs and in the red zone this past season. If the Niners can go from “dreadful” to “good” in those areas, they’ll have no holes on their team.

And if all it takes to make that possible is Rogers signing somewhere else, it will be worth it for the Niners, don’t you think?

Greg Cosell expanded on his NFC championship commentary Thursday morning on KNBR’s The Murph and Mac Show. Here’s what he said.

Q: For everyone who didn’t read your blog, tell us your evaluation of the game.

COSELL: “Let me just start with this: It was 49ers football. They played true to their character. It’s a run-based offense. It’s a high percentage of two backs, two tight ends, two backs and two tight ends. Occasional shot plays, pass plays off play action, off boot action. That’s what they do. The touchdown to Davis, the first one – really beautifully designed, great throw by Alex Smith. The second touchdown to Davis – beautifully designed, another great throw. And we know that if Kyle Williams doesn’t fumble, maybe they win the game. He fumbled twice. That’s 49er football – they did not turn the ball over this year. They were +28 in turnover differential. But the problem is what happens when that doesn’t happen? And history suggests that type of thing never happens two years in a row, by the way, that kind of turnover differential.

“But there are other plays in the game – designed, big-play opportunities that were there, and Alex, for whatever reason – and he knows it, by the way – he didn’t pull the trigger. I don’t know whether he didn’t see it well. I can’t answer that.

“The first play of the second half was about as vivid as you could get. You know that’s a designed play because they came out of halftime with it. It was one of their staple plays – what we call a wheel route. They had Delanie Walker on a wheel route from the line of scrimmage tight end position. He ran right by Corey Webster who slipped. He was wide open. There was no pressure on Alex. Only he can tell you why he didn’t throw it. It would have been a 68 yard touchdown, and he ended up getting sacked.

“There are other examples as well. Michael Crabtree is taking a ton of abuse, and he’s certainly not been worthy of the tenth pick in the draft – we all know that. But, on the first play of a drive with four minutes to go and a tie game, Crabtree is wide open on a corner route from the slot, no pressure on Alex Smith – he left the pocket and then threw it out of bounds. These are plays that you have to make in these games.

“Now, am I going to say he’s the reason they lost? No, I think that would be a little strong. But, I think in tight games like that when everything doesn’t go right that’s gone right for your team all year, that’s when your quarterback has to make throws, and there were a few he missed. Obviously, if Kyle Williams didn’t do what he did they might still have won the game.

“When your turnover differential doesn’t work in a given game – and by the way, you can’t count on that. It worked out phenomenally this year, but I’ve done studies, a lot of people have done studies, a lot smarter people than me have done studies – that kind of thing doesn’t happen year after year after year. So, the +28 will not likely happen next year, and when that doesn’t happen – when other things that you expect don’t happen, the magnitude’s of the quarterback’s play increases. That’s just the way the NFL is.”

Q: But what if you look at Alex Smith’s performance this way – that he did throw two touchdowns, that he didn’t turn the ball over. He did what he did all year, and that’s been enough.

COSELL: “That’s the argument. You could argue he did exactly what he’s done all year and if it wasn’t for the turnovers they very likely could have won the game. But, they had turnovers. So, therefore, when that happens your margin for error lessens and your quarterback has to make throws.”

Q: Did Alex Smith outplay Eli Manning in that game?

COSELL: “I don’t think so, personally. Eli threw 58 balls and he had the living crap beat out of him, so you have to give him credit just in that area, that he kept getting up. I believe he was hit 23 times.

“He should have thrown two picks, maybe three. But the one thing I like about Eli – he has amnesia. He just plays one play to the next. He could throw a horrible ball and then the next play he plays like that didn’t happen. I think that’s one of his strengths.

“Eli is a more talented passer. He can make some throws that Alex Smith can’t make because he’s got a stronger arm and he’s more willing to make those throws. Quarterbacks who are willing to make stick throws, which by the way you have to be willing to do in this league, will always at times appear that they force a couple and they might throw a few more picks. But, in this league, in critical moments you’ve got to be willing to make stick throws into small windows.”