Redskins Coach Jay Gruden says the team’s tackling needs improving, but he’s pleased with the progress of the run defense this preseason. (Jonathan Newton / The Washington Post)

Through two preseason games, the Redskins have yet to have all of their pieces in place on defense because of injuries and ongoing rehabilitation processes. The makeshift starting unit has yet to put on a flawless performance, which is understandable. But Coach Jay Gruden draws encouragement from one major element of the attack: run defense.

The unit as a whole has proved especially stingy against the run, holding Cleveland and Detroit to a combined 91 rushing yards.

Washington’s starting defense held the Browns to just 11 rushing yards in their limited action in the preseason opener, and last week against Detroit, the Redskins gave up only another 11 rushing yards to the Lions’ starters.

This comes without the services of left outside linebacker Ryan Kerrigan, one of the team’s top run-stoppers, and fellow outside linebacker Junior Galette, who still is working his way back from a torn pectoral muscle.

Washington’s defensive line has made an impact, however. The trio of Stephen Paea, Terrance Knighton and Jason Hatcher have proven disruptive in the trenches, while backups Chris Baker, Ricky Jean Francois and Kedric Golston have all rotated in to contribute to the cause.

Thus far, it’s hard to tell if the strong effort against the run has come more because of new defensive coordinator’s institution of more one-gap assignments (where his linemen set up in the gaps between the offensive linemen across from them, rather than lining up head-to-head with them as was the case under Jim Haslett), or if it’s more of a result of the new personnel brought in over the offseason.

“I think a little bit of both. I think our interior defensive line, we’re pretty deep,” Gruden said. “So, we take our first unit out and the second unit is as good as our first unit too. We have a lot of depth on the defensive line and some offensive lines in preseason games don’t have that same depth as we do on defense. So, I attribute that to the depth and good solid tackling.”

The unit still must shore up its tackling. The Detroit game featured more missed tackles than the Cleveland matchup. However, Washington’s defenders did do a good job of swarming to the ball, so if one player missed, another arrived shortly after to clean up for his teammate’s mistake.

Gruden wants to see the missed tackles corrected, but he remains encouraged.

“Our tackling does need improving,” Gruden said. “I think we missed 10-12 tackles throughout that game [against Detroit], but for the most part we are doing a very good job of tackling.”