TAMPA, Fla. -- Just days after Tampa Bay Buccaneers coach Bruce Arians reaffirmed their commitment to running the ball, Ronald Jones suffered a fractured pinkie that required surgery and a pin to stabilize the bone Tuesday. Then Wednesday, he was placed on the reserve/COVID-19 list, meaning either he tested positive for the virus or was deemed a close contact of someone who did.

Jones, who has quietly amassed 900 rushing yards this season (fourth-most in the league), wasn't ruled out for Sunday’s game against the Atlanta Falcons (1 p.m. ET, Fox) for the injury. Arians had hoped he would take practice reps Friday, if not Thursday. But his status on the Reserve/COVID-19 list, which came down several hours after Arians spoke Wednesday, changes that, increasing the likelihood that they will have a new starter Sunday.

Jones would need to pass five straight days of tests if he was a close contact, or at least 10 days if he tested positive and after symptoms passed.

If Jones can't go, here’s how they’ll divvy up the touches for their running backs against the Falcons.

Fournette would be the starter

Leonard Fournette had overtaken LeSean McCoy as the third-down back this season but was benched Sunday in favor of McCoy, whom quarterback Tom Brady advocated to get more involved in the offense.

Since neither Fournette nor McCoy play special teams in Tampa, one’s opportunity often times this season has come at the expense of the other. Arians doesn’t believe Fournette’s confidence was rattled by the decision.

“He’s in a great spot. He understood everything last week and he understands everything this week. He had a great practice today,” Arians said. “Leonard’s a pro. Just like everybody else on our team, it’s a week-to-week thing.”

Fournette’s produced an up-and-down season with the Bucs since his late arrival just prior to Week 1, rushing for 271 yards on 69 carries and three touchdowns, along with 28 catches for 171 receiving yards.

At times he’s looked magnificent, rushing for 103 yards and two touchdowns against the Carolina Panthers in Week 2, including a 46-yard game-winning run in the fourth quarter. Some even called for him to overtake Jones for the starting role afterward.

But then at other times, he’s looked timid and lacked his usual burst. In fact, since his Week 7 performance against the Las Vegas Raiders, when he rushed for 4.55 yards per carry and produced 47 receiving yards on six catches, he hasn’t averaged more than 3.5 yards per rush in a game. His three drops against the Los Angeles Rams were also baffling, as he’s never had a game with multiple drops in the NFL.

He does give them some flexibility in playcalling though, as he does have more natural hands than Jones. His 75.7% receptions per target rate is tops among the Bucs’ RBs, as are his 6.11 yards per reception and 6.39 yards after the catch per reception. He’s also produced a 10.8% drop rate, which is the lowest among their running backs.

The key in all this: Where is his head at? Arians said he’s fine, but Fournette also admitted he had a rough time when Arians decided to sit him last minute for an extra week in Week 6, before acknowledging that Arians had his “best interest at heart” in keeping him healthy. Did his benching last week wear at his confidence or light a fire?

"Just like every back -- every back wants to touch the ball, and when those guys are not in there, they're all pissed off," assistant head coach/run game coordinator Harold Goodwin said. "That's a good thing. At the end of the day, there's only so many carries for so many guys. And at the end of the day, there's a lot of guys, but there's only one running back on the field, so they just gotta suck it up."

McCoy would be the third-down back

McCoy notched third-down runs of 10 and 14 yards in the third quarter Sunday against the Minnesota Vikings -- the first action he’s seen in a game since Week 6, as Fournette overtook him for the third-down back role, which relegated him to more of a pseudo-coaching role with younger teammates. It was a role he embraced without complaint.

In fact, Fournette credited McCoy for helping him keep a positive mindset with his ankle injury and adjusting to his new situation, which was a far cry from what he experienced as the primary running back in Jacksonville, although McCoy acknowledged it wasn’t easy.

“I’ve been waiting. I haven’t really had that many practice reps. And that’s really been tough for me in my career,” McCoy said. “I’ve never had that. I think even last year with the Chiefs, I got banged up and they switched the roles with the running backs, I still was, like, involved.

"But hey, it’s football. I’ll get my conditioning back where it needs to be. I’m starting to get more practice reps. I’ll be ready to play.”

With McCoy’s conditioning admittedly not where it needs to be due to lack of reps, it makes sense to let him try to re-settle into his third-down back role versus starting this week. The Bucs’ third-down role is also not solidified going forward.

“I think he trusts all the guys,” Arians said of Brady. “Each week, each game plan is a little bit different depending on who we’re playing and who’s the best matchups. Shady did a good job last week, obviously. We’ll just see how it goes. We’ll play it by ear each week.”

In terms of blitz pickup, which is crucial for third-down backs, McCoy was overpowered by New Orleans Saints linebacker Demario Davis on a third down that resulted in a sack of Brady for an 8-yard loss in Week 9. He’s produced a 66.7% pass block win rate on nine dropbacks.

While he’s not as physically overpowering as Fournette, the biggest thing McCoy has going for him right now is the trust of Brady, which can’t be understated, given how much he depended on that position in the passing game in New England. The key is, how much rust will there be?

Where do Vaughn and Barner fit?

Ke'Shawn Vaughn, a rookie third-round draft pick, is less likely to get many looks down the stretch, given his limited reps this season and late start in training camp due to battling COVID-19, although he was active against the Vikings -- and unlike McCoy and Fournette, he does play special teams.

Vaughn demonstrated big-play ability when he caught a game-winning, 9-yard touchdown pass from Brady against the Los Angeles Chargers. But he was also credited with a fumble in Week 5 against the Bears.

The Bucs also have Kenjon Barner, whom they called up from the practice squad to take over on special teams for Jaydon Mickens. His action this year has almost exclusively been on punt and kick returns and he doesn’t really factor into the equation on offense unless there are significant injuries.