Sometimes an NFL team can keep its starting offensive line intact an entire season, but Washington Redskins offensive line coach Jim Hanifan knows that doesn't happen too often.

As a result, even after the preseason tinkering had been long gone, his charges haven't been practicing just one position. They've been practicing several.

Hanifan said that has made his job more of a challenge -- particularly given that he's in his first year with the Redskins after taking over for Joe Bugel, now coach of the Phoenix Cardinals.

"But in another way," Hanifan said, "it's kind of fun too. You get to kind of pop it to them. It keeps them alert. All of a sudden -- boom -- they're in over here, or over there. . . . They have to be thinking."

Dealing with a coach who views this kind of activity as fun may be a daily pain for the Redskins' linemen, but it has helped save them as they head into a fifth consecutive week with a different lineup.

Some of the changes were coaching decisions, such as Mark Adickes replacing Russ Grimm at left guard following the loss to Philadelphia in Week 9 and Grimm reclaiming his spot the following week.

Most, however, have been because of injury. Ed Simmons sprained his knee against Philadelphia and was replaced at right tackle by Joe Jacoby. Simmons healed in time for Week 12's game against Miami, so Jacoby returned to the bench. But when Grimm bruised a shoulder, Jacoby moved in at left guard.

Now, with Simmons tearing ligaments in a knee, Jacoby will move back to right tackle, Raleigh McKenzie will move from right guard to left guard and Mark Schlereth from the bench to right guard.

The only constants this season have been Jeff Bostic at center and Jim Lachey at left tackle. But all of the shuffling has been handled without fanfare, without upheaval and, until yesterday's signing of rookie lineman Scott Beavers off waivers from the Broncos, without roster moves.

"Jim {Hanifan} does a good job of making sure guys get a certain amount of reps at the position they will be playing and a certain number of reps at different positions," Jacoby said. "That's the way we've been working it since training camp. So, I think everybody on this line is capable of playing any position or any side of the line."

Jacoby has shown his versatility, having started at left tackle, right tackle and left guard during his Redskins career.

Hanifan said Grimm and McKenzie can play center, both guard positions and, in a pinch, either tackle spot. Grimm, of course, used to be the emergency quarterback.

Lachey and Adickes can play either guard or either tackle. Bostic can play either guard, in addition to center.

This rare kind of flexibility is a confluence of athleticism, intelligence and willingness, Hanifan said.

"It's difficult mentally, let alone physically" to make position changes, Hanifan said. "But they're all good, sharp guys. They can pick up and understand things. They make quick adjustments. They're damn good at that."

Bostic said it is not difficult for players to switch sides of the line. The adjustments come when players have to switch positions.

"Some of the technique changes from tackle to guard," he said. "I don't think center and guard are that different except at center, you're a little bit closer to who you're blocking."

Jacoby did fine against the Bears even though he was switching from tackle to guard, a position he had not played in a game since 1981.

"It's totally different from what I've been used to," he said. "It's a little tighter in there and things go a little bit faster. You're not out on an island. You have guys on both sides of you and things are coming at you. It was fun. I enjoyed it. It seems like we did things pretty well."

Despite the lineup changes, in the last four games the Redskins have yielded a total of four sacks, none against New Orleans and Miami.

Meanwhile, the running game has flourished. Running back Earnest Byner has rushed for 100 yards or more in three of the last four games. In their last two games, the Redskins have rushed for 222 yards on 47 carries and 151 on 31 carries -- 186.5 yards per games and nearly 4.8 yards per carry.

With 290-pound Lachey playing outside 310-pound Jacoby on the left side and Simmons playing very well on the right, the Redskins seemed to have gained some momentum last week. "I felt like we really had found something," Coach Joe Gibbs said.

But the deck will be shuffled again.

"I don't think it's going to be devastating," Bostic said. "You hate to lose Ed. You hate to see him injured, but the cold, hard fact is we have a game to play Saturday. We'll work again, whoever's in there."