Redskins cornerback Josh Norman is back in the weight room but will not play Sunday after fracturing a rib. (Alex Brandon/Associated Press)

Ten days after fracturing a rib in the Washington Redskins’ Week 4 loss at Kansas City, cornerback Josh Norman was back in the weight room at Redskins Park on Thursday and proclaimed it “a huge step” in his recovery.

But he wasn’t able to offer a timetable for his return, still in the early stages of a recovery that Redskins officials said could take as long as four weeks.

“I’ve played through all kinds of injuries, but this one sat me down,” said Norman, 29, the team’s highest-paid defensive player. “It was tough. For me, I never experienced anything like that. … It’s a huge step just to get back in there and do some work to where I was doing nothing for a week and a half — almost two weeks — just laying down and taking it easy.”

Norman hasn’t missed an NFL start since the 2014 season, when a concussion sidelined him for two games while with the Carolina Panthers.

With the Redskins’ bye week following the Oct. 2 loss at Kansas City, Norman said the severity of his injury didn’t hit him until he missed his first day of practice this week.

He’s certain to miss Sunday’s game against San Francisco. If he’s sidelined a full four weeks, he wouldn’t return until the Oct. 29 game against the Dallas Cowboys.

Norman said he focused Thursday on lower-body exercises — working on the treadmill, the elliptical machine and some leg work — while mixing in very light arm pulls.

“I was excited about that because that was the first thing I could do,” Norman said.

His next step is upper-body work. Because the fracture makes it uncomfortable to take deep breaths — coughing and even yawning are uncomfortable at this stage — Norman isn’t ready to get back to running. He said it’s possible he could start running next week.

Meanwhile, Redskins Coach Jay Gruden is readying third-year player Quinton Dunbar, who entered the NFL as a wide receiver, to help shoulder the load at cornerback for Sunday’s game against the San Francisco 49ers (0-5).

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