The Redskins’ situation at OT is dire enough that they signed Jordan Black on Monday, knowing that he only weighs 275 pounds and needs another 15 by the end of training camp. Black said he’s going on a 7,000-calories-a day-diet to add weight.

The Redskins need all the help they can get at tackle. Starting RT Jammal Brown’s future is uncertain as the Redskins await results of his MRI on Tuesday. The depth at T already was thin. Black becomes the Redskins most experienced backup. Second-year Maurice Hurt and rookie Tom Compton are the top backup Ts, but Hurt will play LG until Kory Lichtensteiger returns. Five-year vet James Lee has been unimpressive in camp.

Enter Black, who has made 40 starts in 80 career games but was out of football last year. He’s not worried about being a lighter tackle.

“Lucky for me this is probably the only scheme in the NFL to allow the linemen to be a little undersized,” he said. “I’ve seen it done by people who have done it a little lighter. It’s possible.”

RG3 Update: QB Robert Griffin III spent most of the time working on his passing with only an occasional run. But the few times he did run, it was obvious that he knows how to handle ball fakes and read defenses. He’ll pull the ball out of the RB’s stomach at the last second, forcing impatient defenders to commit early or be fooled. Griffin also showed an ability to escape jams in the pocket. But his intermediate accuracy is inconsistent.

Rookie report: RB Alfred Morris will be an intriguing player to watch during the preseason. It’s hard to tell how effective a RB is until the games begin. With no tackling in practice it’s difficult to see how a runner handles contact. But can be seen of Morris is he runs with a good forward lean and he’s an economical cutter, wasting little movement. He’s scrappy in pass protection, though his technique needs work as he’s lost some one-on-one battles.

Ouch: FB Darrel Young strained his left hamstring and will miss up to two weeks, coach Mike Shanahan said. If Young can’t play in the season opener the Redskins can use their TEs at that spot or even employ an occasional two-RB set. WR Josh Morgan didn't practice after slightly straining his hamstring. He’s day-to-day. OT Willie Smith (knee) also didn't practice. RB Tim Hightower didn't participate in the full-team work.

Star of the day: CB DeAngelo Hall did what he does best. Ballhawk. On the first play of the 11-on-11 portion, Griffin slightly rolled to his left and threw back deep to Pierre Garcon running a post vs. Hall. But Hall lept and broke up the pass. On the next play, Hall wasn’t fooled by a Griffin play-action pass to Leonard Hankerson and stepped in front. Hall dropped the pick, but he had a heck of an afternoon.

Stormy weather: Lightning midway through practice forced the Redskins to move indoors and finish without fans in attendance.

Follow John Keim on Twitter @CBSSportsNFLWAS or @John_Keim.