Chris Thompson leaves Tampa Bay Buccaneers punter Chas Henry and others behind on a 69-yard punt return for a touchdown. (Jonathan Newton/The Washington Post)

For rookie running back Chris Thompson, the span between the Washington Redskins’ preseason finale Thursday night and the team’s roster reduction Saturday was a high-anxiety time. The fact that Thompson had scored a dazzling touchdown on a punt return in the final exhibition game in Tampa hadn’t convinced him, he said, that making the season-opening roster was a certainty.

“Nah, not at all,” Thompson said. “It was only one touchdown. You know, had I had three or four, I probably would have felt a little better. But it felt good.”

There was no need, as it turned out, for the fifth-round draft choice from Florida State to have fretted so much. The team’s coaches had been enamored all along with his speed and big-play capabilities, and Thompson’s 69-yard touchdown on a first-quarter punt return against the Buccaneers came with the Redskins searching for a punt returner after losing Richard Crawford to a season-ending knee injury suffered earlier in the preseason. The team kept Thompson on its 53-man roster as its fourth tailback and, quite possibly but not yet officially, its top punt returner.

When he arrived at Redskins Park on Saturday, one of the team’s strength coaches congratulated him. Even then, Thompson said, he wasn’t sure he’d made it.

“At first, I was kind of like, ‘What are you congratulating me for?’ ” Thompson said following Monday’s practice. “I hadn’t seen the depth chart, all that kind of good stuff. Once I went down and looked at the depth charts and everything, I saw my name on there.”

The Post's Mike Jones talks with Jonathan Forsythe about the Redskins preseason and whether the team's four wins are an indicator of good things to come for the regular season. (Post Sports Live/The Washington Post)

Being on the roster instead of being relegated to the team’s eight-man practice squad hadn’t looked like a sure thing for Thompson for most of training camp and the preseason. The Redskins were well stocked at tailback with Roy Helu Jr., Evan Royster and Keiland Williams also vying for roster spots behind highly productive starter Alfred Morris. And there wasn’t a need for a return man until Crawford, a reserve cornerback, was hurt on a punt return in the third preseason game.

Enter Thompson, who filled in capably for Crawford in that game and then had his big moment in Tampa. He joins Morris, Helu and Royster on the depth chart at tailback. Williams was released and another rookie running back, seventh-round pick Jawan Jamison, landed on the practice squad after being waived Saturday.

Redskins Coach Mike Shanahan declined to name Thompson the team’s punt returner for Monday night’s season opener against the Philadelphia Eagles at FedEx Field, saying that wide receivers Santana Moss and Josh Morgan also remain in the mix.

“Chris is definitely a top candidate as well as Santana and Josh Morgan,” Shanahan said. “Those are our three candidates going into the game.”

But Shanahan said his formula for determining which players will be active on game days includes a spot for a “wild-card” player, such as a return specialist, who might not necessarily be in the plans on offense or defense. That could be Thompson, although the coaches will have to be convinced of his reliability after he fumbled twice on offense during the preseason.

He is settling in as a returner, he said, after not returning punts since high school.

“I’m starting to feel more and more comfortable every single day,” Thompson said. “I mean, that punt return helped me out a whole lot with my confidence back there. So I’m just gonna continue to keep getting better at it and just keep working, and I’ll keep feeling more and more comfortable. And then it’ll just be one of those things that’s second nature.”

Playing time on offense could be difficult to come by. Morris set a single-season team rushing record last season as a rookie, and Helu and Royster have had smaller doses of NFL success in the past when given opportunities. But Thompson said he will do his best to be ready if needed.

“I’m prepared for whatever the coaches want me to do,” Thompson said. “Over the course of this long season, you never know what happens. Guys go down every single year. I hope everybody stays healthy. But you know it’s football so you never know what’s gonna happen. So I just continue to prepare every single day and if Coach calls my name, I want to be ready.”

In the meantime, he is likely to be given a chance to be a game-changer on special teams. Thompson’s preseason breakthrough came at the end of a rookie-year training camp in which he missed some practice time while working his way back from the torn anterior cruciate ligament in his left knee he suffered during his final college season. Thompson also suffered two broken vertebrae in 2011.

But Thompson is healthy now and he’s on an NFL roster, with the cutdown-day stress finally beginning to dissipate.

“I was hoping that I made it,” Thompson said. “But it was a sense of relief big time. Even when I came out to practice the other day, I still felt nervous and I don’t know why. But it didn’t go away until [Sunday] night.”