MIAMI -- The running back position is a modern-day enigma in the NFL. They were once highly drafted, but now teams are struggling with how to value them properly.

Because of a running back's relatively short prime and heavy wear-and-tear, many teams have shied away from drafting them in the first round, opting for late-round or undrafted backs at a more reasonable price point. Miami Dolphins coach Mike McDaniel has been a purveyor of that movement over the past five seasons.

Since taking over as the San Francisco 49ers' run game coordinator in 2017 and being promoted to offensive coordinator in 2021, three of McDaniel's leading rushers were undrafted, one was taken in the sixth round and the other was a second-round pick of a previous regime.

Over that span the 49ers rank 11th in team rushing yards, the Dolphins 31st. Myles Gaskin (612 yards) and Duke Johnson (330) were the leading rushers for Miami last season, when it ranked 30th at 92.2 yards per game. It's clearly an area that must improve under McDaniel, but presents an interesting dilemma -- whether to shoot for one of the premier running backs in the 2022 NFL draft or venture toward McDaniel's method.

However, the fact that some of his most effective rushers have been undrafted belies the importance McDaniel places on the position.

"The value of the running back position -- what value do you put on anywhere from a third to a half of the plays on a given offensive season?" McDaniel said at the NFL scouting combine. "You got to realize running backs, collectively ... you have about 300 to 400 some touches, so it's incredibly valuable, but there is a more diverse way of finding them.

"From a historical perspective, there is rookies, second-year players, mid-to-late-round [draftees] that have more success at that position than some others. But it's ... of paramount importance. We just have a concrete skill set that we found that can really flourish in a zone-blocking system."

The Dolphins haven't taken a running back in the first round since selecting Ronnie Brown with the second overall pick in 2005. They have drafted 14 running backs since, with only five coming in the first four rounds.

General manager Chris Grier has taken four running backs in the seventh round since 2019, but with a floundering rushing offense and strong prospects presumably available in the second and third round of this year's draft, there could be a temptation to break that streak in 2022. Especially with few options available at the top of the free-agent market.

"If there is that talent that is just so unique that you have to take him -- people argue whether Saquon Barkley worked out or not, but he was an extremely talented football player," Grier said of the running back picked No. 2 overall by the Giants in 2018. "So you kind of go through those and make your judgments, but at the end of the day you always do what's best for your team.

"Mike's had a lot of success finding good running backs in that mid-late round in terms of ... going through some of his evaluations talking about it and 49ers people all confirmed it. We had [Kenyan] Drake in the third round a few years ago [2016], so that balance is right. You go with your gut and that information you find out on players."

Two prospects to keep an eye on if Grier opts for a running back in the second or third round of the draft are Michigan State's Kenneth Walker III and Iowa State's Breece Hall, who turned in impressive performances at the combine. Hall, listed at 6-foot-1, 220 pounds, is coming off back-to-back seasons with at least 1,700 scrimmage yards and 23 touchdowns. He is a proven three-down back who can contribute as a runner and a receiver and lit up Lucas Oil Stadium with a 4.39-second 40-yard dash at the combine, which tied him for the third-fastest time among his position group.

Walker, listed at 5-10 and 210 pounds, has fewer touches than Hall and only one year of elite production -- 1,636 yards and 18 touchdowns on the ground for the Spartans in 2021. He turned in the second-fastest 40-yard dash time at the combine with a 4.38, but is not as accomplished as a receiver. ESPN NFL draft analyst Jordan Reid believes Walker is a name to watch for the Dolphins in the second round.

"Grier has attempted to patchwork the running back spot with several late-round picks and in-season additions," Reid wrote before the combine. "In need of a lead option with a high upside, Walker is a potential 1A rusher who could make this team better."