WASHINGTON receiver DeSean Jackson could miss three to four weeks after straining his left hamstring early in the team's season-opening loss.

"Possibly, it could be shorter, but you just never know with hamstrings," coach Jay Gruden said yesterday.

"You hate to lose a star, especially with his speed," Gruden said. "We feel good about the receivers that take his place, but nobody can substitute him for that burning speed that gets down field and scares safeties and corners to death."

Jackson is not the only unwanted change to the starting lineup for Washington (0-1) heading into Week 2 against visiting St. Louis (1-0).

Cornerback Chris Culliver was suspended by the NFL for next Sunday's game because he violated the league's personal-conduct policy. The NFL did not say exactly why Culliver was punished. He was arrested in March 2014 on suspicion of felony hit-and-run and reckless driving and pleaded guilty to two misdemeanors this past June.

And safety Duke Ihenacho will need surgery to repair a fractured and dislocated left wrist.

The Redskins also made a switch at kicker, releasing Kai Forbath and signing Dustin Hopkins in an attempt to improve the team's kickoffs.

Jackson was injured on the first play of Washington's second possession against Miami. He was trying to catch Kirk Cousins' deep throw to the right sideline.

The three-time Pro Bowler led the Redskins with 1,169 yards receiving and six touchdown catches in 2014, his first season in Washington after he was let go by the Eagles, who visit the Redskins in Week 4, Oct. 4.

A shoulder issue kept Jackson from playing in any games this preseason, but Gruden said it's unclear if that contributed to the receiver's current injury.

"He was still able to do a lot of running in that time," Gruden said. "So I don't think it really did [play a role]. I think it was one of those things that happens to a wide receiver."

In other moves, the Redskins re-signed defensive end Frank Kearse after releasing him last week, and waived linebacker Houston Bates.

Noteworthy

* Miami signed Raheem Mostert, the undrafted rookie running back from Purdue who was in the Eagles' training camp. He replaces LaMike James, who was released the day after he fumbled a kickoff return.

In other Dolphins news, the NFL says it will take no action against defensive tackle Ndamukong Suh after he dislodged Redskins running back Alfred Morris' helmet at Washington. The contact by Suh following a play was determined not to be a kick, the league said.

* Kansas City coach Andy Reid defended embattled right tackle Eric Fisher, who has been dealing with a high ankle sprain and did not play in the season opener at Houston. Fisher practiced last week but was not on the field with the starters Sunday. Several reports citing unidentified sources said the Chiefs were upset with Fisher for telling them late in the week that he was not ready to deal with J.J. Watt and the rest of the Texans. Reid denied those reports.

* Cleveland coach Mike Pettine says starting quarterback Josh McCown is following the NFL's protocol on concussions and it's too early to know if he'll be able to play in the home opener against Tennessee.

* Carolina middle linebacker Luke Kuechly has entered the NFL's concussion protocol and his status won't be known until later in the week. Also, rookie tackle Daryl Williams said he'll miss 2-4 weeks with a sprained MCL in his right knee.

* Arizona running back Andre Ellington has a sprained right knee, an injury that's less serious than initially feared. Coach Bruce Arians wouldn't rule him out for Sunday's game at Chicago.

* An MRI revealed New York Jets cornerback Antonio Cromartie has a sprained left knee and hasn't been ruled out for Monday's game against the Colts.

* Oakland quarterback Derek Carr's injured throwing hand that knocked him out of the game Sunday is a bruise, and the Raiders are hopeful Carr will be able against Baltimore. Also, safety Nate Allen will miss time with a knee injury but is expected back this season.

* An MRI revealed that Indianapolis receiver T.Y. Hilton did not sustain any structural damage to his injured left knee in Sunday's loss at Buffalo. He is day to day.

* Houston coach Bill O'Brien said he knows who will start at quarterback against Carolina this weekend, but wouldn't say whether it will be Brian Hoyer or Ryan Mallett.

* San Diego right guard D.J. Fluker is expected to miss considerable time with what is believed to be a high ankle sprain.

* Chicago signed linebacker Sam Acho after releasing him last week and placed defensive lineman Cornelius Washington on season-ending injured reserve because of a quad injury.

* St. Louis coach Jeff Fisher said defensive end Eugene Sims and special-teams ace Chase Reynolds have knee injuries that could sideline them a few weeks.