SANTA CLARA, Calif. -- After an eventful offseason, the San Francisco 49ers running backs group has finally settled in.

Gone is speedy Matt Breida, who was traded to the Miami Dolphins in April. Leading rusher Raheem Mostert -- who demanded a trade, rescinded that request and then received a reworked contract -- is back. Tevin Coleman, who was the Robin to Mostert's Batman last season, also returns, as does promising third-year back Jeff Wilson Jr. And, with a little bit of luck, Jerick McKinnon will finally make his 49ers debut after a knee injury cost him the past two seasons.

It's a crowded room, one that once again has fantasy football players scratching their heads over rating and value. That's always a fair stance to take when it comes to any Kyle Shanahan-coached team, but there does finally seem to be one player who stands above the rest.

That would be Mostert, who burst onto the scene last year with 772 yards and eight touchdowns while averaging a robust 5.64 yards per carry during the regular season. He then tacked on five more touchdowns while averaging 6.34 yards per carry in three playoff games. All of that left Mostert feeling as if he'd earned his spot as the No. 1 back.

"I've got to prepare myself because I am the starting running back and my confidence level is up to the guys that consider themselves to be top backs," Mostert said. "I just want to go out there and be dominant. When I step out on to that field, I want everybody to say, 'That's a bad mo-fo,' you know? He's somebody that we can't take lightly. I want to put fear in other teams' eyes. That's my mindset. Even when I'm playing gunner, I just want people to know that I'm the best special teams' player to ever play this game. And that's the mindset that I'm going to have at running back.

"I want them to know that I'm the best running back to ever play this game even though it doesn't show as far as my careerwise. But I don't necessarily care about that. I always tell myself, once I get that opportunity, I'm never going to look back. That's what I got to hold myself up to, that type of standard."

Mostert posted his breakthrough last season despite not starting a single game and averaging just 6.6 carries per game through Week 12. When he finally got his opportunity to carry more of the load after injuries hit late in the season, he took advantage. From Week 12 through Super Bowl LIV, Mostert led the league with 12 rushing touchdowns, and his 760 rushing yards was second in the NFL. That included the NFC Championship Game against the Green Bay Packers in which he ran for 220 yards (second-most in any postseason game) and four touchdowns.

While that would seem to make him the slam dunk starter, Shanahan has made it clear he likes using Coleman and Mostert in tandem with Coleman starting the game, Mostert in relief and then riding the hot hand. With Coleman back for his second season, it stands to reason that duo will continue to get the bulk of the carries, especially on early downs.

Where things could look different is on third down, especially if McKinnon is able to stay healthy and deliver on the promise the Niners saw in him when they signed him two years ago. At the time, Shanahan had big plans for McKinnon, particularly in the passing game. Without McKinnon the past two seasons, 49ers running backs have produced in the pass game but simply haven't been as involved as Shanahan would like.

Although Niners running backs rank first in the NFL in yards per catch (9.59) over the past two seasons, they are just 18th in receptions (160) and tied for 19th in targets (212).

Don't be surprised if a healthy McKinnon changes all of that and unlocks another part of Shanahan's offense.

"It's a rarity to have a skill-position guy who sees the game like a quarterback still," quarterback Jimmy Garoppolo said of McKinnon. "Jet does a great job of that. Even just throwing routes on air this offseason, he runs them differently than most running backs. He has a feel that's like a receiver but he feels space like a quarterback. It's very unique. I'm excited to get him back, man. It's been a while. We came in together, me and him, when we both signed here. It's exciting to have him back."

There are others beyond the 49ers' big four running backs, too. The problem will be identifying potential. For as long as the Shanahan family and veteran running backs coach Bobby Turner have been locating little-known running backs and turning them into stars, the biggest hint of a possible breakthrough has always come in August.

In the dog days of training camp, stars such as Terrell Davis have emerged in exhibition games, earned opportunities with the starting offense and, eventually, elbowed their way into meaningful carries. It worked for Mike Shanahan in Denver and Washington, it has worked for Kyle Shanahan as offensive coordinator in previous stops and it has worked again for him as the coach of the 49ers.

This year, though, COVID-19 has eliminated the preseason and made the task of finding the next running back diamond in the rough "a lot harder," according to Shanahan.

"It's hard to know how good a guy's going to break tackles until you actually see guys try to tackle," Shanahan said. "Things like that, I think, those will be a little harder to evaluate."

That means players such as undrafted rookie running backs Salvon Ahmed and JaMycal Hasty will have to leave a lasting impression on the practice field rather than under the lights of a preseason game. It has Shanahan considering full-contact practices for guys jockeying for roster spots, something he hasn't done before.