The Post Sports Live crew looks at Robert Griffin III's 2013 statistics and debates how much improvement would constitute a successful 2014 season. (Post Sports Live/The Washington Post)

When the Washington Redskins selected safety Phillip Thomas and running back Chris Thompson in the 2013 NFL draft’s fourth and fifth rounds, respectively, coaches and officials believed they had found a potential difference-maker on each side of the ball.

The team didn’t see a return on their investments last season after both underwent season-ending surgeries. Thomas didn’t play beyond the second game of the preseason; Thompson lasted four regular season games.

Now both find themselves in battles for key spots on the depth chart, but because of injuries, their auditions are on hold again. They find themselves in a precarious position: Every day they are sidelined, they fall further behind in the race for roster spots. But if either were to rush back and play poorly while still not healthy, his chance of making the roster would lessen significantly.

“It’s a slippery slope,” Coach Jay Gruden said. “You push them out there, you get out there too quick and you injure the hamstring and you’re back in the same boat, or worse. . . . They have promise and are exciting in what they can do. But, we’ve got to see it, and we can’t see it if they’re hurt all the time. So, injuries happen, like I said. We understand that. But we’ve got to find a way to get them healthy and on the field as soon as possible so they can show us.”

All Thompson wanted entering last week’s preseason opener against New England was to make some plays to impress his coaches and to emerge healthy. That would put him a step closer toward his goal of earning a key role in Washington’s offense as the speedy, pass-catching complement to Pro Bowl power runner Alfred Morris after missing the bulk of his rookie season due to shoulder surgery.

The Post Sports Live crew debates whether the Redskins new head coach is the opposite of their former head coach. (Post Sports Live/The Washington Post)

Thompson caught a pass Thursday night against the Patriots, picking up five yards. He tried to break it for a bigger gain, but while trying to fight through the grasp of one defender, Thompson felt another fly in and come down on top of him. Pain shot through his ankle; he collapsed and had to leave the game.

Five days later, Thompson has yet to return to the field because of a low-ankle sprain that could force him to miss at least another five days. Meanwhile, competitors such as Roy Helu Jr., Evan Royster and Lache Seastrunk have gotten precious snaps in practice.

“Man, it was so bad to be honest with you, that I just wanted to cry,” the 5-foot-7, 193-pound Thompson said Monday. “I’m telling you, man, my mind-set is so different. I just want it so bad. I can’t explain it, man. Every day it’s killing me not to be out here. I know sometimes we say, ‘It’s just practice,’ but every day is a new opportunity. And especially for me, it could be new opportunities to showcase my skills. So just to be out again, it can be pretty frustrating.”

Thomas knows just how Thompson feels. His start to the season may be even more vexing.

Impressed with his showing during offseason practices, coaches thought Thomas had a chance to earn a key rotational role with veteran Brandon Meriweather or perhaps eventually overtake him for his job.

Thomas entered training camp with confidence, but he strained his hamstring July 31 and watched the preseason opener from the sideline. He hasn’t made it back onto the practice field, either.

“It just seems like one thing after another,” Thomas said. “It’s frustrating. Really frustrating.”

Gruden and his assistants sense the frustration of both players. But they seem frustrated as well.

“It’s disappointing,” Gruden said when asked about Thompson. “It’s unfortunate for him because he was progressing very well, and he needs the reps to do what we’re going to ask him to do on game day, and if he’s not available to get these reps, that’s going to hurt his progress. But injuries happen, and unfortunately for him, it seems like more often than not. He’s got to figure out how to stay healthy.”

Defensive coordinator Jim Haslett’s stance on Thomas was very similar.

“I know he’s frustrated, and as a coaching staff, we’re frustrated because we don’t know if he’s reliable and accountable enough yet from an injury standpoint,” said Haslett. “There’s a fine line there. . . . Time’s running out. I don’t know the consequence, but obviously, it’s not good for him, or for us, if he’s not out there.”

Of the two, Thomas appears to be closer to returning. He did some sprints under the direction of strength coach Ray Wright on Monday. He said he won’t practice Tuesday, and the team has Wednesday off. He’ll return to practice Thursday, and prepare for next Monday’s game.

“I am going to play in this game. I have to,” Thomas said. “It’s something I feel myself because I missed all of last year. I just know I have to get out there.”

Thompson shares Thomas’s sense of urgency, but he knows not only must he return to the field, he must also find a way to stay there.

“I have to get healthy and stay healthy so I can get those reps, get better at what he would want me to possibly do on Sundays, let’s say I do make the team and everything,” he said.