Vikings wide receiver Jalen Nailor (83) gains yards in the second quarter Sunday against the San Francisco 49ers at U.S. Bank Stadium. Nailor ranks second on the team in receiving yards with 75. (Anthony Souffle)

Like so many mistakes made in the sports world, they seemed like reasonable ideas at the time.

In 2023, the Vikings would replace Dalvin Cook with longtime, reliable backup running back Alexander Mattison. The team would save money and, theoretically, get enough production out of the position to keep defenses honest.

The Vikings would count on K.J. Osborn to evolve into a dangerous third receiver. Why not? Osborn had played well in 2022 and had earned a larger role.

What was the risk, really? In the modern NFL, running backs and third receivers are like snow tires. They don’t have to be pretty — just functional.

That was the theory.

The theory was proved wrong.

In 2022, Cook produced 1,458 yards from scrimmage and Osborn had 650 receiving yards. Both played their roles well as the Vikings went 13-4.

In 2023, with Mattison replacing Cook and Osborn facing heightened expectations, both flopped, and the Vikings finished 7-10.

There were plenty of other factors that led to the team-wide failure, including quarterback injuries, but Mattison and Osborn failing directly cost them victories that would have kept them in contention.

Mattison produced just 892 yards from scrimmage (rushing and receiving) and three touchdowns, and his fumbles and dropped passes may have cost the Vikings two or three victories. Osborn managed just 540 receiving yards.

Both were allowed to leave as free agents in the past offseason, and were replaced by Aaron Jones at lead running back and Jalen Nailor at third receiver.

Jones has been everything the Vikings could have wanted. His running and pass-catching have been instrumental in the Vikings’ 2-0 start, and his presence has allowed Ty Chandler to excel as a backup.

Jones and Chandler are both averaging an exceptional 5.5 yards per rush. The only flaw on Jones’ Vikings’ résumé is his fumble on Sunday, and that was the result of a spectacular play by 49ers’ all-world linebacker Fred Warner.

Again, a lot of credit should go elsewhere — to the offensive line, Sam Darnold’s audibles, and the coaching staff. But Jones and Chandler look like they could give the Vikings one of the league’s best rushing attacks.

Nailor ranks second on the team in receiving yards, with 75, and has half of the team’s four touchdown catches. He also sprinted downfield to block a defender as Jefferson completed his 97-yard touchdown catch-and-run on Sunday, justifying his nickname: “Speedy.”

Jones and Nailor, a sixth round pick in 2022, have produced three of the Vikings’ five touchdowns this season. Last year, Mattison and Osborn produced six total all season.

“The combination of those two guys was really impactful, against a very good defense,” Vikings coach Kevin O’Connell said on Monday.

NFL teams have devalued the running back position in recent years, leading to an almost unprecedented trend — the shuffling of standout backs.

The Panthers traded Christian McCaffrey to the 49ers and he almost won a Super Bowl last year.

The Titans let Derrick Henry leave, and he became the Ravens’ starter.

The Packers let Jones leave, then signed Josh Jacobs.

The Bengals let Joe Mixon go, and he went to the Texans as their starter.

The Giants let Saquon Barkley go, and he went to the Eagles as their starter.

Dak Prescott, the highest-paid quarterback in the league, makes $60 million a year. McCaffrey, the highest-paid running back, makes $16 million.

Which means you can get great production and value from the running back position without pushing your payroll near the salary cap limits.

Jones is one of the Vikings’ most important players and personalities, and he’s making $7 million. He’s one of the league’s best bargains.

“I felt I could be incorporated here very well and bring value in this offense,” Jones said Sunday.

Nailor, who is still on his rookie deal, is making less than $1 million in base salary.

For less than $8 million, the Vikings have filled two important positions in their offense with impactful players.

Through two games, their performances rank as one of many signs that in the last year Vikings’ General Manager Kwesi Adofo-Mensah has found his footing.