Jon Jansen earned the nickname "Rock" for his remarkable durability dating back to his days at the University of Michigan. His streak of 80 consecutive starts with the Redskins was something he undoubtedly took great pride in.

Jansen suffered the first significant injury of his career in Monday night's Hall of Fame Game against the Denver Broncos. He ruptured his left Achilles midway through the first quarter.

"I knew exactly what happened when it happened," he said. "There wasn't anybody around me. I just turned to run downfield and it just popped. It felt like somebody kicked me right in the back of the ankle."

Immediately after the game, team officials stressed it was premature to call it a season-ending injury.

Jansen was replaced in the lineup by Daryl Terrell. In the second half, rookie Mark Wilson played at right tackle.

Teammates were stunned to see Jansen helped off the field. Even head coach Joe Gibbs indicated it took the team a while to recover from the injury.

"Jon's a guy who's irreplaceable," quarterback Mark Brunell said. "Obviously he's a great football player and a great leader. The guys all respect him. It's unfortunate to lose him."

Added LaVar Arrington: "He'll have to be strong. He'll have to do whatever he needs to do to get better&It just lets you know that you have to play every game like it's your last one."

After the game, Jansen seemed fully prepared for the rehabilitation ahead.

"For me, it's something that's going to be a challenge I've never had before," Jansen said. "I've never had to be helped off the field and I've never missed a practice. It's disappointing and frustrating, especially with the new coaching staff we have here and all of the expectations."