Kansas City Chiefs running back Jamaal Charles has spent the last few months at his offseason home in Austin, Texas, working out with fellow NFL players such as Brian Orakpo of the Tennessee Titans and Jerrell Freeman of the Indianapolis Colts.

Another member of the regular workout group is Chiefs linebacker Derrick Johnson. He ruptured his Achilles tendon in the season-opening loss to the Tennessee Titans, ending his seasion.

Charles offered this report on Johnson.

“He’s doing pretty good," Charles said. “He looks like he never hurt his Achilles. Dude looks good. He’s got no soreness. He’s not complaining about it. I think he’s excited to get back on the field. I’m going to be excited to see DJ play this year."

The Chiefs would certainly share that sentiment. Their rush defense was one of the worst in the league last season. The Chiefs allowed 127 yards per game and 4.7 yards per rush, both numbers being among the worst in the league.

Johnson’s absence isn’t the only reason. One of the Chiefs’ other top run defenders, end Mike DeVito, also ruptured his Achilles tendon against the Titans and was done for the season. Another, safety Eric Berry, missed more than half of the season because of injuries and illness.

Johnson, a three-time Pro Bowl selection, is the most important component. The Chiefs, like Charles, have been optimistic about the outlook for Johnson in what little they’ve shared since his injury.

Here’s an illustration of what Johnson means to the Chiefs, and in particular their run defense, keeping in mind it’s a small sample size and other factors such as DeVito’s injury are in play:

The Titans rushed nine times for 25 yards, a 2.8-yard per carry average, before Johnson’s injury. They ran the ball 29 times for 137 yards, a 4.7-yard average, after.

We should know more about Johnson next week, when the Chiefs gather in Kansas City for the start of their offseason conditioning program.