WWE boss Vince McMahon would be proud. Vikings General Manager Rick Spielman is pulling no punches while setting the stage for a Mankato Summer Slam Battle Royale designed to forcibly upgrade an offensive line that has disappointed too many people for far too long.

"If you create competition, either guys are going to rise up or get beat out," Spielman said Thursday on KFAN radio while discussing the acquisition of guard Alex Boone, the team's No. 1 target in free agency. "That means you got better."

Actually, the O-line battle royale began weeding people out of Winter Park within hours and days of the wild-card playoff loss to Seattle two months ago. First, coach Mike Zimmer stepped into the ring, tossed offensive line coach Jeff Davidson over the top rope and declared that no lineman's job would be safe after Teddy Bridgewater faced more pressure than any other NFL quarterback last season, according to Pro Football Focus.

When asked two days after the season why he didn't renew Davidson's contract, Zimmer didn't even try to sugarcoat his dissatisfaction.

"Because I didn't want to," Zimmer said.

Later, in a quieter transaction, Zimmer pitched strength coach Evan Marcus over the turnbuckle, firing him as well. That also was a move made with the big fellas up front in mind.

In two years under Zimmer, the offensive line had a lack of cohesion on the field and a suspect environment in the weight room. Three of the team's five pectoral injuries suffered in 2014-15 were to offensive linemen. Meanwhile, in 2015, center John Sullivan was slated to come off injured reserve when he needed a second back surgery after reinjuring himself in the weight room.

As the start of the free-agency negotiating period neared on Monday, the Vikings sharpened their focus on the offensive line. Rather than cut right tackle Phil Loadholt, they negotiated a significant pay cut with no financial guarantee. They also signed exclusive-rights free-agent tackle Carter Bykowski, gave a one-year deal to right guard Mike Harris and put in place the four-year, $26.8 million deal that Boone inked when the signing period began Wednesday.

Thursday afternoon, Spielman exhaled long enough to pack a bag and head to the airport for a flight to Columbus, Ohio, and Friday's Ohio State pro day. His attention shifted to the draft while others in the front office continued to focus primarily on retaining the team's top three free agents: linebacker Chad Greenway, cornerback Terence Newman and tight end Rhett Ellison.

But that didn't mean Spielman was done with free agency after signing Boone, safety Michael Griffin and linebackers Travis Lewis and Emmanuel Lamur. In fact, Bengals free-agent tackle Andre Smith was due to visit on Sunday, per an NFL source.

With Boone on board, the Vikings have 14 offensive linemen. Eight of them have been a regular starter in the NFL. Seven have at least four years of experience.

"A lot of the stuff we tried to do this year was accumulate as many of these young guys as we can and keep as many as we can," Spielman said before the NFL scouting combine last month. "I'm always going to try to keep shuffling these offensive linemen in.

"Last year, I know Carter Bykowski got hurt with his pec, but we got him off San Francisco's practice squad. To me, if you can just keep flinging through here — Mike Harris was a claim guy when he got released from San Diego — so you got to constantly turn that position over and constantly keep finding the right combination of guys."

Financially, the Vikings will have a lot of flexibility when the competition hits the field in front of new line coach Tony Sparano, who steps into the fray with unbiased eyes, a fresh approach and a more aggressive mentality. Loadholt and Sullivan, both of whom are over 30 and didn't play last season because of injuries, have no guaranteed money left on their deals. And Loadholt, Joe Berger, Zac Kerin and Jeremiah Sirles are in the last year of their contracts.

Left tackle Matt Kalil also is in the final year of his contract. The team decided to keep him for the $11.96 million salary that came with the fifth-year option in his rookie deal.

With that kind of salary and signs of improvement after a poor 2014 season, Kalil is the likely starter at left tackle. Boone is a natural lefthanded player and is the presumed starter at left guard, although his size (6-8, 300) and skill set could make things interesting if Kalil falters or right tackle continues to be a weak spot.

Center, right guard and right tackle are clearly up for grabs.

"Oh yeah," Spielman said. "That's what I want."

At this early point of the offseason, center could go to Sullivan, who played well in 2014; Berger, who filled in and was the team's best lineman in 2015; or long shots Kerin or Nick Easton. At right guard, there's presumed front-runner Brandon Fusco, a former right guard who struggled at left guard last year; Harris, the former tackle who started at right guard last year; and Austin Shepherd, an extra blocker in short-yardage situations last year. At right tackle, there's Loadholt; T.J. Clemmings, who started but struggled as the starter there last year; Bykowski and, of course, Smith if he were to sign with the Vikings.

Then there's the draft.

"We also want to bring in some rookies," Spielman said. "Hopefully, they'll be able to contribute like our past rookie draft classes have been able to."

NFL rules and roster limits prevent Spielman from putting a 20-man offensive line in front of Bridgewater. The more players he adds, the more players he's going to have to get rid of at the end of training camp. But that's OK, Spielman said.

"Some of those guys, you can possibly trade because you know they can play for other teams," Spielman said. "And you can't predict injuries. If you have quality people and two or three players fighting for a starting spot, if you lose guys for the year, you have quality depth behind them.

"When you come down to having to make those 53-man decisions, you want to have very tough decisions to make."

Mark Craig covers the NFL for the Star Tribune. mark.craig@startribune.com