It’s a cold-hearted business sometimes, this NFL.

And if we all didn’t have a true understanding of that concept already, Tuesday provided another eye-opening example.

Cornerback Antoine Winfield had gone to the Vikings’ facility, per his usual routine, to work out. He had no way of knowing that would be his last trip into the building. About an hour before free agency opened, as the Vikings sorted through some complex financial discussions, Winfield became just a number.

Two numbers really.

$7.25 million – what he was set to earn in 2013, a figure that could be cleared from under the Vikings’ salary cap if Winfield was released before the new league year opened at 3 p.m. Tuesday.

1977 – Winfield’s birth year, which will make him 36 years old when next season begins.

In decisive form, General Manager Rick Spielman made a business move, void of emotion. He summoned Winfield upstairs and told him he was cut. The awkwardness of that move and the confusion it created for one of the most beloved players in franchise history is detailed in our story from last night. We suggest you give that a read and soak it in.

But to understand the maneuver from a business standpoint, it must be noted that Spielman and the front office were active Tuesday in re-signing several of their own players. A half-dozen of them in all. Most notably: right tackle Phil Loadholt and fullback Jerome Felton. Loadholt reportedly inked a deal worth $25 million over four years. Felton was given a $7.5 million contract over three years.

The Vikings also rewarded linebacker Erin Henderson, safety Jamarca Sanford, receiver Jerome Simpson and offensive lineman Joe Berger by keeping them around.

Spielman’s vision for the future forces him to make such tough decisions. As this week goes on, and really as the Vikings’ plow ahead from now through the end of the draft in April, they will do so with a plan. And then a Plan B. And Plans C, D, E and F.

“This is a very fluid business,” Spielman noted Tuesday.

And so even the GM acknowledged the conflicting emotions of such a busy day.

“When you have to make tough business decisions, it makes it extremely hard. One minute you’re elated because you got Phil Loadholt done and the next minute you don’t feel as good because you had to do something with Winfield, which makes this job extremely, extremely difficult.”

What made Winfield’s release all the more confusing for the cornerback and his agent is the lack of discussions that preceded it. At no point, during the league’s 87-hour negotiating window from Saturday through Tuesday where teams and agents could be in contact, was there any hint that Winfield could soon be on the street. No one from the Vikings front office even proposed a pay cut or contract restructuring.

Winfield and his agent knew, in this league, that’s always a possibility. But they didn’t expect, after nine seasons of service, that in the snap of two fingers, a loyal locker room leader would have a trap door opened beneath him.

Sure, the Vikings had talked with Winfield’s agent, Ashanti Webb, at the NFL Combine in Indianapolis three weeks earlier. And yes, in passing, the Vikings had mentioned just generally that Winfield’s $7.25 million salary could catch their eye as free agency nears. But, according to Webb, the conversations in Indy were casual, informal. No specific proposals were drawn up. And none were offered Tuesday when Winfield was released.

Spielman was asked if he had offered Winfield a chance to stick around at a lower cost.

“I don’t want to get into the details of it,” he said. “It was just a very, extremely hard decision to make but hopefully we’ll be able to keep the door open for him.”

Four days before free agency began, I had approached an NFL source to ask whether the Vikings had been in contact about a contract restructuring. They hadn’t, the source told me. And even if they did, it wasn’t something Winfield was going to consider.

Said the source: “The way he played last year? Please. You need to look at the game film and not the birth certificate. The only way Antoine is taking a pay cut next season is if the NFL decides to suddenly up its AARP taxes.”

So who knows what would have happened had restructuring discussions come up between Spielman and Webb? The fact is, for three weeks leading up to free agency, that possibility was never brought up. It led to a very unceremonious end of a terrific Vikings career.

By late Tuesday afternoon, as you might imagine, calls inquiring about Winfield’s availability were pouring in. The message was made clear. Even if Winfield’s days as a Vikings were over, his career is not. He fully intends to play next season. And, if 2012 is any indication, he can still play at a high level.

Spielman repeatedly noted Tuesday that he would leave the door open for a possible reunion with Winfield in the weeks or months ahead. What would that take?

“We’ll just have to see,” Spielman said.

He shall see just how much other teams value Winfield’s service. He shall see if the manner in which Tuesday’s transaction went down will leave Winfield itching for a new home. By all accounts, amid the awkwardness and confusion, Winfield handled Tuesday’s business with his characteristic professionalism and positive energy. On the way out the door, the Vikings encouraged Winfield to keep in contact and to report back to them with any numbers that might be out there for him in free agency.

It now becomes one of the more interesting subplots around the NFL.