Rob Jackson will miss the first four games of the 2013 season. (The Washington Post)

Redskins linebacker Rob Jackson and defensive end Jarvis Jenkins this week began serving their four-game suspensions without pay for violating the league’s policy on banned substances. But Jackson is allowed to be at Redskins Park during his suspension while Jenkins cannot.

Jackson’s suspension fell under the drug abuse policy, but Jenkins’ ban came as a result of violating the league’s policy on performance enhancing drugs.

Related: Jenkins, Jackson about to start serving suspensions

Jackson’s suspension stemmed from a failed drug test late last year that he blamed on his taking a pain medication (for a bad tooth he eventually had pulled) that had been prescribed to his girlfriend and not him.

A change in the collective bargaining agreement is what gave Jackson the freedom to have contact with his teammates and train at the facility even though he still isn’t getting paid and can’t practice or play.

Jackson was in the locker room during Wednesday morning’s media availability session and was getting ready to work out while his players readied for practice.

“I’m really glad they changed it,” Jackson said of the policy, which was modified several years ago. Jackson said the main benefit is he can continue to train at he team facility, which will make it easier for him to remain in shape while waiting to make his return.

The Redskins have a bye in Week 5, so Jackson and Jenkins’s first games back will both be Oct. 13 at Dallas.

Have a Redskins question? E-mail Mike Jones at with the subject line “Mailbag question” for him to answer it in The Mailbag.

What’s ahead:

● Posts on Alfred Morris, Barry Cofield and Chip Kelly’s relationship with Robert Griffin.

● The NFL season kicks off with Baltimore in Denver on Thursday night.

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