Indianapolis ? Safety Bob Sanders spent the past four weeks painfully watching the Indianapolis Colts’ defense flounder.

He might finally get a chance to help it out Saturday.

Against Larry Johnson and the Kansas City Chiefs in a first-round playoff game, Sanders hopes to give the Colts a timely reminder of how this defense is designed to work.

“We’ve got to be fast, we’ve got to get off blocks, we’ve got to get into the gaps,” Sanders said. “And we’ve got to have fun.”

Neither Sanders nor his defensive teammates have had much to celebrate this season.

Sanders, who made the Pro Bowl last season, missed 12 of the last 14 games after having arthroscopic surgery on his right knee. His absence exposed the Colts’ oft-criticized defense for what it lacks without him: an energizing playmaker.

At 5-foot-8, 206 pounds, he is built like a cannonball, hurls himself toward runners like a missile and is at his best in run support.

Without him, the Colts simply aren’t the same.

In 2005, Sanders earned a trip to Hawaii after helping the Colts allow the second-fewest points in the league. This season, with Sanders primarily on the bench, the run defense dropped to No. 32 and set a franchise record by allowing 5.3 yards per carry.

Coach Tony Dungy warns Sanders cannot solve all the team’s defensive problems, but when he plays, the Colts are clearly different. The defense plays quicker, more aggressively and with more confidence.

In a November game at New England, Sanders made a surprise start and the defense delivered one of its best performances of the season. Not surprisingly, Sanders had 10 tackles, an interception and took down runners with reckless dives. The Patriots averaged 4.5 yards a carry, had five turnovers and lost 27-20.

Sanders’ impact is so strong that his offensive teammates sometimes notice, too.

“When he’s healthy, he’s a special player,” said tight end Dallas Clark, a college teammate of Sanders at Iowa. “It’s just instincts and God-given talent the way he can read and run. It’s natural to him. He was born to be a football player.”

But lingering soreness and swelling in the knee created frustration for Sanders.

His name has been more prominent on the weekly injury reports than the lineup card, and whenever it appeared he was close to returning, Sanders endured yet another setback.

Dungy spent the past several weeks saying he thought Sanders would play before the regular season ended. It didn’t happen.

On Tuesday, Sanders tested the knee in practice, and after practicing for a second straight day Wednesday, the Colts were more optimistic. It’s the first time since having surgery Sanders has practiced two consecutive days although he’s still listed as questionable.

While he insists the knee is healthier and stronger than at any time since surgery, Dungy needs Sanders’ teammates to feed off his emotion and style.

“One person can’t do it, and Bob Sanders can’t be a savior,” Dungy said. “Everyone has to do their job and Bob is a big part of that. We’ve got to make sure everyone is in the right place and use our speed.”

Sanders’ return will also be a welcome respite to a secondary that has been beaten up, sometimes badly this season.

He understands the defense, doesn’t hesitate to make plays and is one of the team’s top tacklers – all problem areas for the Colts.

What Sanders must still answer, though, is how quickly he can return to full speed. He’s played only one game in the last two months and acknowledges it might take a few plays to shake off the rust.

If Johnson, the NFL’s No. 2 rusher with 1,789 yards, happens to get in the way, even better, because Sanders is ready to start hitting again.

“Knowing the defense and where you’re supposed to be, I think I’ll be able to help them,” he said. “I’m looking forward to it.”