Free safety Jarrad Page was placed on injured reserve Wednesday, and he’ll miss the rest of the season because of the severely pulled calf he suffered during last Thursday’s practice.

The Chiefs signed cornerback Travis Daniels, who spent training camp with Kansas City, and began a shift of their defensive backfield that could, in a pinch, involve nickel back Maurice Leggett playing safety.

Leggett made an appearance at safety during the loss two weeks ago to San Diego, and coach Todd Haley said Wednesday that Leggett, a second-year player, has some experience at the position — which suddenly is a significant weakness for the Chiefs.

“I feel like we’re at least ahead of the curve with him,” Haley said. “It’s an area of concern, obviously, for us. We’ve been cross-training some of those corners to be alert in an emergency situation, if we were to have something happen. … We’ll be tenuous, to say the least, as we go forward here, at least for this week.”

Free safety Jon McGraw, who had become the starter after Page couldn’t shake a nagging shoulder injury, also is hurt. He missed Wednesday’s practice because of a thigh injury, and his status for Sunday’s game at Jacksonville is unknown.

Charles checks out Titans’ Chris Johnson

Haley said second-year running back Jamaal Charles, who is expected to start Sunday and be counted on for a significant number of carries, was assigned weeks ago to study a video of Tennessee running back Chris Johnson.

Charles, like Johnson, is a thin running back but with plenty of speed. Charles is listed at 5 feet 11 and 199 pounds, the same height but one pound lighter than Johnson’s listed size.

Haley said he wouldn’t mind if Charles emerged as a similar rusher as Johnson, who rushed for 228 yards on 24 carries in a win last week against Jacksonville. Weeks ago, Haley said, assistant head coach Maurice Carthon delivered a tape of Johnson’s performances to Charles and assigned him to study what has helped Johnson become one of the NFL’s most dynamic young runners.

“There are some similarities there,” Haley said. “If you’re built like somebody else or have a similar skill set, that’s a pretty good guy to watch.”

Sunday could be the best opportunity Charles gets to prove he’s capable of being the Chiefs’ featured back. Larry Johnson is suspended, and Kolby Smith could be activated but isn’t likely to get many carries.

“Jamaal is his own person,” Haley said, “and he’s got a great opportunity here.”

Derrick Johnson improves his standing

Inside linebacker Derrick Johnson, who has undergone an inconsistent season in which he has lost his starting job and has yet to earn it back, at least has won back some good favor with Haley.

But favor isn’t yet enough to unseat Demorrio Williams, who Haley said was a bright spot for the 1-6 Chiefs.

“Demorrio Williams is not a reason why we’re where we’re at,” Haley said. “He’s played as good of football as anybody on this team. I have no problem with how Derrick is preparing, practicing and playing. I have no problem at all with Derrick and what he’s doing. He’s continuing to get himself ready, so when an opportunity — a bigger opportunity presents itself, he’s ready for that.”

Other injuries

Chiefs safety Jon McGraw (thigh) and cornerback Mike Richardson (illness) did not participate in Wednesday’s practice. Center Rudy Niswanger (knee) was limited, and left tackle Branden Albert (ankle) was a full participant.

For Jacksonville, cornerback Scott Starks (hamstring) missed Wednesday’s session, guard Maurice Williams (knee) was limited, and cornerbacks Rashean Mathis (finger) and Brian Witherspoon (hamstring) were full participants.