While the Vikings are upgrading their offensive line by re-signing right tackle Phil Loadholt, signing free-agent guard Alex Boone to a four-year deal worth $26.8 million, and still hoping to sign free-agent tackle Andre Smith, the biggest addition they might have made is new offensive line coach Tony Sparano.

Sparano has a long history of coaching in the NFL, including stints under coaches Marty Schottenheimer, Tom Coughlin, Rex Ryan and Bill Parcells in Dallas (along with Vikings coach Mike Zimmer).

Sparano, who was the head coach for the Dolphins for four seasons (2008-11) and served as interim coach with the Raiders in 2014, posted a 29-32 record with the Dolphins, including an 11-win season and a playoff appearance in his first year there.

Now Sparano will be tasked with improving an offensive line that helped the team rank fourth in the NFL in rushing (2,211 yards), but 31st in passing (2,928) and tied for the eighth-most sacks allowed (45).

Sparano said working with Zimmer at Dallas from 2003-2006 got him interested in being on Zimmer's staff in Minnesota when offensive line coach Jeff Davidson was fired in the offseason.

"My association with Coach Zimmer started when I was with the Dallas Cowboys," Sparano said. "He was the defensive coordinator there and I was the line coach there under Parcells. We got a chance to work with each other and always liked what his philosophies were, and now I get a chance to work with him here."

Sparano helped turn Dallas around, much as he did in Miami when he took over that team. The Dolphins went from one win the previous season to 11 wins in 2008.

"We had good success [in Dallas]," he said. "We went to the playoffs a couple times and when we walked into the Cowboys with Coach Parcells, I think they were [5-11 for three consecutive seasons] and we turned it around and went 10-6 the first year there. I think probably the last year there we [went 13-3 in 2007]."

Key position

The Vikings are at a crossroads with their offensive line in several regards, after preseason injuries to Loadholt and center John Sullivan left them starting Joe Berger for 16 games at center and rookie T.J. Clemmings 16 games at right tackle last season.

After those early injuries, the team did have great consistency with Berger, Clemmings, Matt Kalil, Brandon Fusco and Mike Harris all starting 16 games, but it's clear the team wasn't pleased with the line's overall play and is looking to add depth and competition for training camp.

Sparano, who got his start as an offensive line coach at Division II New Haven, has been coaching offensive lines and tight ends for the bulk of his career.

"I've coached the offensive line a bunch of different [NFL] places," he said. "Started in Cleveland with the Browns. Certainly with the Dolphins, I was the head coach but had my eye on the offensive line there. With the Oakland Raiders, with the Dallas Cowboys, four or five different stops."

Sparano, like Zimmer, is known to have a direct and intense coaching personality, but he said sometimes that is necessary, especially when coaching a group of offensive linemen.

"I think as a coach, the players take on the personality that the coaches give them," he said. "One of the things you have to be in that room, I think you have to be a little bit fiery. You have to have a good demeanor to be able to get the guys to understand what it is you're asking them to do, but I think you have to have a lot of passion to coach that position."

Help in draft?

Sparano joined Zimmer in Indianapolis for the NFL scouting combine. Many mock drafts have offensive tackle Laremy Tunsil of Mississippi going first overall, but Sparano said there was a lot of offensive line talent available, though he doesn't know if the Vikings will aim for one of them early.

"There's a bunch of good players out there right now and we're in the middle of evaluating them all right now, so we'll see how it all shakes down," he said. "But there were certainly some players that could help us.

"Overall, I think there's going to be several [offensive linemen] going in the first round. … The last four or five years, that position has probably turned out five or six first-rounders in the draft each year."

The Vikings are on their way to having one of the best defenses in the NFL, being overseen by a defensive genius in Zimmer. Now with Norv Turner as offensive coordinator and new coaches Sparano and Pat Shurmur (tight ends), there's a good chance the offense will start rising to equal the defense.

Jottings

• I'm a big booster of Beth Goetz and believe she should be named the Gophers' permanent athletic director, but I can't understand how the university can hire Ayo Taylor-Dixon, or any other associate athletic director, until the permanent director is named. Minnesota hired Taylor-Dixon on Friday.

• A Vikings official reported that the Chelsea-AC Milan soccer match, which could be the first event held at U.S. Bank Stadium in August, is still not a done deal.

• Timberwolves point guard Ricky Rubio is finally finding himself on the court, tying his career high and the franchise record with 17 assists in the Wolves' heartbreaking 107-104 loss to Phoenix on Monday. Rubio also tacked on 13 points for his 11th double-double of the season. He had 15 points and 11 assists against Memphis on Wednesday, giving him an impressive five double-doubles in six games. … Zach LaVine has averaging 18 points and 32.7 minutes over his past 23 games. He's shooting a sensational 50.9 percent from the field over that stretch and 42.7 percent on three-pointers.

• Two former Gophers basketball coaches made the postseason. Tubby Smith and Texas Tech earned a No. 8 seed in the NCAA tournament and face Butler at 11:40 a.m. Thursday. Dan Monson made the NIT with Long Beach State, who finished 20-15 this season after losing in the first round 107-102 to Washington.

• All five Gophers men's track and field athletes who went to Birmingham, Ala., for the NCAA indoor track and field championships earned All-America status. Luca Wieland was named to the first team in the heptathlon. Luke Johnson (shot put), Ryan Lockard (high jump), Gian Ferretti (weight throw) and Goaner Deng (800 meters) earned second-team honors.

Sid Hartman can be heard weekdays on 830-AM at 7:40 and 8:40 a.m. and on Sundays at 9:30 a.m. shartman@startribune.com