Linebacker Rob Jackson (50) after scoring a touchdown last season against the Bengals. (Toni L. Sandys/The Washington Post)

The Washington Redskins are not yet committing to having defensive end Jarvis Jenkins and linebacker Rob Jackson in their playing rotation during Sunday night’s game in Dallas.

Jenkins and Jackson are back after missing the first four games of the season while serving suspensions for violations of the league’s drug policies. But defensive coordinator Jim Haslett said Thursday it’s not yet clear what roles, if any, the two will play against the Cowboys.

“We’re still kind of in an evaluation process with those two,” Haslett said. “I think they’re in pretty good shape based off what I saw just for two practices Monday and Wednesday. Again, we’ll see how they go today, tomorrow and then we’ll sit down with Coach [Mike] Shanahan to figure out how we want to use them, activate them, all that. But right now we’re still in the evaluation process with those guys.”

Jenkins was to be a starter at defensive end this season. Jackson was to be a key reserve behind outside linebackers Brian Orakpo and Ryan Kerrigan.

Haslett said Thursday he’s confident that the Redskins eventually can find ways to use Jackson effectively this season even with both Kerrigan and Orakpo in the lineup. Jackson made 14 starts last season with Orakpo hurt and finished with four interceptions and 4.5 sacks. But finding playing time for all three of those players, Haslett said, is an issue for down the road.

“I don’t even know if he’ll dress [for the Dallas game] yet, from that situation,” Haslett said of Jackson. “Again, a guy misses a month. You’re trying to go through the evaluation process. First of all, you try to find out where he’s at physically. Then mentally, what did he retain because you’re talking about three days work, going to play a game. We’ll work it and see where he’s at the end of the week.”

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

What’s ahead:

● Mike Jones on the Redskins’ preparations for the Cowboys’ 4-3 instead of 3-4.

More on the Redskins and NFL:

Jenkins: Translating Snyder’s letter on the team name | Snyder’s letter

Forbath healthy and kicking well | Garrett says Griffin is still a worry

The Outsider: Reviewing Redskins blitzes that worked against the Cowboys

Morris still eager to carry Redskins’ load | Cofield: Redskins’ confidence not shaken

Opening Kick: Should Redskins do HBO’s ‘Hard Knocks?’ | 49ers’ Harbaugh open to it

Follow: @MikeJonesWaPo | @MarkMaske | @Insider | Insider on Facebook

Bold Predictions from Post Sports Live:

The Post Sports Live crew offers bold predictions for the Redskins game at the Cowboys on Sunday. (Post Sports Live/The Washington Post)