It's been said ad nauseam since Ron Rivera became the Redskins' head coach in January, but he loves position flexibility, particularly on the offensive line.

"I believe in it," Rivera said at the NFL Scouting Combine. "If they can go tackle, guard, guard, center, center, tackle, you've got something special there. Guys that do give you an option to move guys around, but also you won't have to tip your hand."

Rivera has backed up that philosophy since he started making changes to the roster; he's either drafted or signed six offensive linemen -- the most additions for any position -- and nearly all of them have some experience playing at multiple positions.

Two of the newest players -- third-rounder Saahdiq Charles and fifth-rounder Keith Ismael -- are among those who offer that valued trait, and it might be enough to help them get on the field sooner than people think.

"Every opportunity for anybody to come in and play is here," Rivera said. "We are going to play the guys that we believe give us the best opportunity to win football games."

Charles and Ismael have their preferred spots on the offensive line. Charles was the left tackle on LSU's 2019 unit that won the Joe Moore Award for college football's best offensive line, while Ismael primarily played center and was a three-time All-Mountain West selection.

But both have a history of playing at two and even three positions. Charles started games at right tackle and guard with the Tigers, while Ismael has played center and both guard spots since his freshman year.

"My offensive line coach, [San Diego State offensive line] coach [Mike] Schmidt, he put a lot of responsibility on me to lead the line," Ismael said after he was drafted. "Wherever he needed me week-in and week-out, I was ready to play. He rotated me in over my years at right guard and at center, so I feel comfortable playing all positions."

Wherever Ismael played, the Aztecs were rewarded with excellence. Pro Football Focus gave him a pass-blocking grade of 88.8 -- the best of any offensive lineman -- on 474 pass-blocking snaps in 2019. He also had a run-blocking grade of 77.3, giving him the sixth-highest overall grade (80.3).

Rivera called Ismael a "stout, physical football player" and added he and vice president of player personnel Kyle Smith "always feel good" about someone who can help them at multiple positions.

"Wherever they need me, I'm willing to put the work in to contribute," Ismael said.

The Redskins plan to move Ismael around in his rookie season, but the starting center position is already filled by four-year veteran Chase Roullier. However, the starting left guard and left tackle spots remain open.

"He's a guy that has a chance to contribute early on, and quite frankly, because we're starting over, we're starting from the beginning, everything is on the table," Rivera said.

Only two of Charles' 28 starts came at a position other than left tackle, and he excelled at the position. Clyde Edwards-Helaire, Nick Brossette and Redskins running back Derrius Guice all had 1,000-yard rushing during his career, and he helped protect Joe Burrow during his Heisman Trophy-winning season. PFF gave him the only elite pass-block grade in the College Football Playoff National Championship with zero pressures on 61 pass-block snaps.

Smith, who called Charles a "high talent player" with "tremendous upside," said he and Rivera are excited about adding him to the roster.

"We feel very confident in the kid, we're comfortable with everything, the research that we've done," he said. "We're excited about the structure that we're going to give this kid, the culture that Coach [Rivera] was talking about that we're going to provide this kid."

Whoever becomes the starting left tackle will have the responsibility of protecting second-year quarterback Dwayne Haskins Jr. The Redskins' offensive line was tied for 18th in sacks allowed, per Football Outsiders, with an adjusted sack rate of 7.2%.

It sounds like Charles is up for that challenge; he already wants to find where Haskins' launch point is and communicate with the quarterback.

"I take a lot of pride in that, and it's one thing we took a lot of pride in as an offensive line at LSU," Charles said of his pass protection. "Two seconds of strain and an extra two seconds of pain and finish and [keep] the quarterback clean."

Rivera said he also wants to see what Charles can do at left guard. He believes in cross-training players and hopes learning the responsibilities of both positions will help Charles' growth.

"It'll be an opportunity to see what his skillset is and see how versatile he truly is."

The Redskins went into the NFL Draft with questions on the left side of the offensive line, and perhaps Charles or Ismael can provide some answers. If they can prove themselves whenever training camp begins, their versatility gives them a good chance of finding ways on the field.

"You feel good about those kinds of guys, because again, they're not pigeon-holed into one position and one position only," Rivera said. "There's an opportunity for us to find ways to use them, to get them on the field. And that's a way for the player to also try and use his talents to get on the field...as quickly as possible."