On Thursday afternoon — the day after they'd agreed to new deals with Anthony Barr and Shamar Stephen, and just over an hour after they'd restructured Everson Griffen's deal to help make it all work — the Vikings showed off their work in the first phase of 2019 free agency as a hallmark of their philosophy.

"Days like today are really important to me because without the ownership and the way they help us to keep guys like Anthony and Shamar, it's really, really important and dear to us," coach Mike Zimmer said. "They're both great people. That's kind of the type of players we're trying to get here: Great people, great players who want to learn and get better, [be] great people in the locker room and help each other get better. They'll always be Vikings and they'll always be Zim guys."

Barr and Stephen also play on the side of the ball where the Vikings have invested a significant amount of their capital since hiring Zimmer in 2014. Even after saving $3.8 million in cap space by restructuring Griffen's deal, the team still has the third-most cap space in the NFL invested on its defense, according to Over the Cap. And with roughly $6 million left in cap space, the Vikings still have an offseason to-do list highlighted by the offensive line, where Danny Isidora — he of 361 career NFL snaps — is the only guard on the roster who's played in a regular-season game.

The Vikings figure to need roughly $2.5 to $3 million to sign their draft picks, and likely will retain some money to deal with in-season surprises, such as when they needed to sign kicker Dan Bailey after releasing rookie Daniel Carlson last year. And while they could explore additional ways to clear cap space through the remainder of the offseason, they'll have to address the rest of their needs carefully.

When asked Thursday if the Vikings had enough cap space to sign another starter in free agency, a kicker or their upcoming draft class, General Manager Rick Spielman said, "Maybe, maybe not" to all three questions.

"We've had probably tons of things that we've explored and are continuing to explore," Spielman said. "There's a lot of things that can happen between now and the draft. There's a lot of things after the draft that can happen. You're always adding. You never know opportunities that come your way on potential trades or whatever. So we'll just see how everything evolves, but it never ends. I'll just say that."

The Vikings — who made Brian O'Neill just the third lineman Spielman has selected in the first two rounds of the draft last year — could be helped by what's considered to be a strong class of offensive linemen this year. They could also explore lower-tier free agents such as former Falcons tackle Ryan Schraeder, in whom they've reportedly shown interest. Schraeder, who was released by Atlanta in February, wouldn't factor into the NFL's formula for determining 2020 compensatory picks, and thus wouldn't jeopardize the Vikings' chances of obtaining a high pick for losing Sheldon Richardson to the Browns.

"We're going to make sure we're prudent with our decisions," Spielman said. "I have a pretty good sense of the strengths and weaknesses of what's in free agency, and I have a pretty good sense of the strengths and weaknesses of what's in the draft. I know also with the addition of the new offensive staff, some things from a schematic point that we'll do differently will also help. When you have players sometimes that aren't top-line players, they find ways to schematically hide some of those weaknesses."

Their quest to improve the offensive line, by now, is a familiar offseason task for the Vikings. But a year after giving a deal to Kirk Cousins that turned the football world on its ear — and days after wooing Barr back from the Jets — the Vikings will have to take a nuanced approach to the rest of their offseason shopping.

"If we do have another thing going on and free agency and stuff — and I've read the tweets — our cap is planned through this whole process," Spielman said. "We have to have a cap plan; where do we have to be to sign our draft picks? What do we have to be at by September in order to have enough money in the bank if we have to go out and get replacement players as guys get hurt? We don't plan it like, 'OK, Day 1, this is where our cap is going to be.' We've got a cap-planning thing, what do we have to be in May and where do we have be at when the 53 [players on the regular-season roster] come in. It's a year-round financial plan as you go through the process."