If football does start up front like the axiom states, one can look no further in hope of a potential turnaround for the 2021 Minnesota Vikings defense than the overhaul on the line.

It is quite likely that all four Week 1 starters will be players who did not play for the Vikings in 2020.

Danielle Hunter is back after missing all of last season with a neck injury. Stephen Weatherly also has returned to Minnesota and could man the other defensive end spot. An injury disrupted Weatherly's first year as a starter in Carolina.

Weatherly will compete with Jalyn Holmes, who is the one member of the 2020 Kickoff Weekend starting defensive line who is still with Minnesota, and other young players.

After opting out of the 2020 season because of COVID-19 and a pre-existing condition, Michael Pierce got vaccinated once he was eligible and is expected to be a force in the middle. The Vikings brought in Dalvin Tomlinson when 2021 free agency opened to pair him with Pierce.

Minnesota then brought back Sheldon Richardson in June. Richardson was a starter for Minnesota in 2018 before signing a lucrative deal with Cleveland.

It will be good to see how that group meshes during U.S. Bank Vikings Training Camp because stopping the run and sacking quarterbacks are best accomplished with symphonic play.

With camp on the horizon, here are three key questions for the Vikings defensive line.

Can Hunter produce the way he did before his injury?

Hunter's sixth pro season ended without a sack or even a snap in full pads. The NFL's youngest player to record 50 career sacks suffered a neck injury during a camp practice that required surgery.

The absence of a player who had posted 14.5 sacks in 2018 and 2019 was glaring. Minnesota finished with a paltry 23 sacks last season and struggled to make opposing quarterbacks uncomfortable.

The Vikings were led in sacks by Yannick Ngakoue, who recorded 5.0 in six games before he was traded about as fast as he had been acquired.

That was just the 19th time in 60 Vikings seasons that at least one player had not recorded a sacks total in double figures and first since 2007 when Ray Edwards, Ben Leber and Kenechi Udeze each recorded 5.0.

Jared Allen was acquired in 2008, and he delivered 14.5 sacks in each of his first two seasons in Minnesota. The leader of the "Mullet Militia" led the Vikings in the category in all six of his campaigns with the club. Hunter did so thrice in his first five seasons and won't turn 27 until late October.

We won't use this space to speculate on Hunter's recovery. He did not practice during Minnesota's mandatory minicamp but said he's good to go. He has shown some superhuman strength and athleticism for a man his size over the years. If he's fully healthy, there's no reason to think he won't achieve the success he did before the injury.

What does the ideal rotation look like for the defensive tackles?

It was funny to hear Harrison Smith describe his reaction to learning the Vikings added Richardson in June.

Minnesota already was looking forward to Pierce becoming available based on his accomplishments in Baltimore. The anticipation is that he'll handle the nose tackle that Linval Joseph adeptly manned from 2014-19.

Pierce's personal best for defensive snaps in a season was 594 in 2017 when he was on the field 54 percent of the time for the Ravens. Joseph's snap counts ranged from a career-high 729 in 2014 (67 percent) to a low of 529 in 2015 (49 percent). He played 719 in 2016 and 663 in 2017, making the Pro Bowl after each season. Joseph played another 669 in 2018 and 552 in his final season with the Vikings.

We don't know if Pierce will be asked to assume a larger role, but he might not have to with the additions of Tomlinson and Richardson.

Tomlinson did not miss a single game in his four seasons with the New York Giants, and he played at least 558 defensive snaps each year, capping with a personal high of 658 in 2020.

Richardson has only missed seven games and has started 118 of a possible 128 during his eight-season career. He's never played fewer than 618 snaps and has played at least 718 in each of the past three seasons.

That's three bona fide starters for two positions, but 2021 success might be best defined by enabling each defensive tackle to maximize his own snaps. Minnesota could go with Pierce at nose tackle and Tomlinson at the 3-technique on early downs when run plays are more probable then, quickly sub in Richardson with a rush unit on third downs that are likely to be passes. Maybe Richardson also would be the go-to when offenses are in two-minute drills.

Assistant Head Coach/Co-Defensive Coordinator Andre Patterson will have plenty to work with as he continues to lead Minnesota's defensive line.

Who is ready for another step forward at defensive end?

Weatherly, a seventh-round pick in 2016, appeared in 49 games and made seven starts with 6.0 sacks during his first stint in Minnesota. The Vikings were glad to bring him back after he made nine starts for the Panthers in 2020.

He'll compete with several other players with less experience. Holmes has moved between defensive end and defensive tackle during his first three seasons. He started nine games in 2020, but his lone career sack occurred on Oct. 21, 2018.

D.J. Wonnum is looking to build on a solid rookie season in which he recorded 3.0 sacks that included forcing a fumble by Aaron Rodgers at Green Bay. Hercules Mata'afa and Jordan Brailford are back in the fold, and Kenny Willekes is eager for his first NFL action after missing all of last season with a camp injury. The Vikings also drafted Patrick Jones II in the third round and Janarius Robinson in the fourth.