Mike Shanahan insists he isn’t bluffing. The Washington Redskins coach maintains he isn’t engaging in the usual NFL subterfuge and merely keeping his plans under wraps when it comes to his team’s running back situation.

He really has no idea, he says, who will be carrying the ball when the regular season arrives in September, whether one of the leading training-camp candidates — Tim Hightower, Roy Helu or Evan Royster — will emerge as a centerpiece runner or if coaches will be left to mix and match and patch together a tailback-by-committee arrangement.

“You guys kind of tease me a little bit, saying that I won’t say,” Shanahan said in front of a group of reporters late Friday at Redskins Park, after the team had completed its second practice of training camp. “I don’t know. I don’t know who’s going to be the tailback. I do know that I have three guys I have a lot of confidence in that played last year. . . . We’ll find out.”

As proof of his anything-can-happen hypothesis, Shanahan offered the example of the rookie year of Terrell Davis, his standout tailback in Denver, in 1995.

“People asked me about Terrell Davis,” Shanahan said. “They didn’t think he was going to make the football team going into the last preseason game, but he had a heck of a game. So we really don’t know who’s going to play. Maybe [Redskins rookie running back] Alfred Morris is the guy who steps up, just as Davis did. That’s why you have to have competition.”

Davis ran for 1,117 yards as a rookie in Denver to begin a magnificent four-year stretch in which he surpassed 1,500 rushing yards three times and helped Shanahan and Broncos quarterback John Elway to a pair of Super Bowl triumphs. Now Shanahan, after beginning his Redskins tenure with two seasons in which the team totaled only 11 victories, is looking for the runner — or combination of runners — to best complement rookie quarterback Robert Griffin III.

“We’ve got a lot of guys who can play,” Royster said. “It’s a competition right now and we’re all looking to get the starting spot. We want this team to win. But we all want to play.”

Shanahan had an uncanny knack in Denver for finding productive tailbacks without always having to turn to a highly celebrated player. Davis was a sixth-round draft pick. After Davis stopped churning out 1,500-yard seasons, the Shanahan-coached Broncos got 1,000-yard rushing seasons by Olandis Gary, Mike Anderson, Clinton Portis, Reuben Droughns and Tatum Bell.

The Redskins have yet to have a 1,000-yard rusher under Shanahan. The NFL is, more than ever, a pass-first league, so having a single workhorse runner no longer seems necessary for success.

But the Redskins would like to give Griffin all the assistance they can, and putting a productive runner in the backfield would mean defenses could not just key on the rookie quarterback. Shanahan’s system, with its zone-blocking approach by the offensive linemen, is a proven asset to a running game, but the Redskins also must pick the right runner or runners.

There has been speculation about the possibility of the Redskins adding a veteran free agent at the position; CBS reported last week there had been discussions among team officials about signing either Cedric Benson or Ryan Grant. But one person familiar with the situation played down that possibility, particularly in the case of Benson.

The Redskins say their priority is to see if any of the running backs currently on the roster can handle all of the position’s responsibilities, including blocking, on a full-time basis.

“If we can get a guy that can do it all, obviously we’d like to leave that guy in and play all the time,” Shanahan said.

Said Royster: “We want to play and we all want to be the number one guy. We want to be the next Emmitt Smith, those types of guys. That’s what we all strive for.”

Hightower was the starter before suffering a torn anterior cruciate ligament in his left knee last October. He was on the field for Thursday’s opening practice of camp but has been told by Shanahan to avoid over-doing things in his return. Shanahan said Friday it’s clear to him that Hightower’s knee is “not even close to 100 percent, but I see improvement every day.”

Helu led the team with 640 rushing yards last season as a rookie, and averaged 4.2 yards per carry. Royster averaged 5.9 yards per carry last season, and ended his rookie year with consecutive 100-yard rushing performances against the Minnesota Vikings and Philadelphia Eagles. Royster said his comfort level is higher now as a second-year pro. He said coaches have told him that he looks less nervous. The Redskins like his instincts and elusiveness.

“He makes people miss,” Shanahan said. “He knows how to cut. He knows when to cut.”

The three have divided practice-field snaps.

“You want to be the guy who goes in there and competes your tail off here to see where the chips may land,” Helu said.

Shanahan declined to name Hightower as the starter last season before his injury, or anyone else the favorite for the job.

“Our play will determine that, and how we push each other is going to determine that,” Hightower said. “Come that first game, the best man will be on the field.”

The competition is likely to play out over the entire preseason — and perhaps longer. Helu said he could envision roles continuing to evolve during the regular season.

“I think,” Helu said, “it goes till February.”