A fire rekindled inside Mike Boone in mid-November.

The Vikings' No. 3 running back, Boone was backing up Dalvin Cook — who was challenging for the NFL rushing lead — and Alexander Mattison, a breakout rookie.

But when Cook suffered a chest injury Nov. 17 in a victory over Denver, Boone's practice runs became particularly aggressive. Vikings coach Mike Zimmer noticed Boone's fresh legs setting a tempo as starters lost some energy thanks to the wear and tear of the first 11 weeks of the season.

If Boone stopped long enough to look around in practices this week, he'd see nobody in front of him in the Vikings backfield. The second-year running back is set for his first NFL start Monday night against the Packers after again taking first-team handoffs from quarterback Kirk Cousins on Friday. Cook, who has continued to have problems with chest and shoulder injuries, and Mattison (sprained ankle) remain sidelined.

" 'Monday Night Football,' " Boone said. "As a kid that's what you dream of, to be able to be in this position to possibly be out there. It means a lot."

The hyper pace continued this week for Boone as the Vikings' No. 1 back in practice.

"Any short-yard runs, make them feel me," Boone said, "and convert to get the first down. That's about it."

It's unclear how long Boone's turn leading the backfield will last. A committee approach is possible as Ameer Abdullah will be involved to some extent on passing downs and fullback C.J. Ham is a trusted pass protector who can sub at running back. But how the 24-year-old Boone has embraced roles on kickoff, kickoff return and punt return teams gives Zimmer confidence despite Boone having played only 36 offensive snaps this season.

"He's really been champing at the bit to play," Zimmer said. "That's why he's been doing such a great job for us on special teams, because he just wants to get on the field."

The Vikings offense is preparing for the possibility Cook likely will sit out the final two regular-season games, a league source told the Star Tribune. Mattison, another league source said, is dealing with an ankle sprain suffered Dec. 8 on the first play of the last drive against the Lions and is not expected to be ready for a full workload by Monday night.

"[The Lions] have some pretty big linemen," Mattison said Friday. "One of them grabbed me over the top and went over my back. Ended up in a bad position and it popped a little bit, just recovering from that. It's feeling good, just taking it day by day trying to make sure I'm good to go whenever that is."

Vikings coaches and executives have raved about the roster's backfield depth since a 2018 competition led to five running backs, including Ham, making the 53-man roster. Boone again made the cut in September after another strong preseason, including a 21-carry outing against Seattle during which he added a 45-yard catch and run.

Boone didn't get an invite to the NFL combine and went on to post vertical and broad jump numbers that topped every running back invited in 2018 before the Vikings signed him as an undrafted free agent out of Cincinnati. He said the Vikings backfield prides itself on rolling deep.

"Do the same things as Cook and it won't be a drop-off," Boone said.

Boone's success Sunday against the Chargers, including two short-yardage touchdown runs, was no surprise to teammates who have watched the former two-star receiver recruit from Glen St. Mary, Fla., evade tacklers for two NFL preseasons.

Now it's time for Boone, an exhibition star averaging 4.8 yards per carry in August, to show what he can do for an offense that runs the ball more than any NFL team except Baltimore and San Francisco.

"That's Mike," Cook said. "That's why we trust all our guys. We got guys in the backfield that can shoulder the load. You saw that on Sunday with Boone stepping in, C.J. taking carries. It shows a next man up mentality, and that's the type of mentality we got in that room."