Left tackle Trent Williams noticed the difference in his play every once in a while. A block not finished here. Another one not executed there. But Williams also knows something else.

“A couple years ago I may have wanted to shut it down,” he said, “and not play through that type of pain. It was a lot of discomfort.”

There’s a reason he played every snap despite a bone bruise in his right knee,   which caused him to limp around Redskins Park most of last week. And it has to do with his four-game drug-related suspension at the end of last season.

“Yeah, that’s the driving force behind a lot of things I do now,” Williams said. “I made a mistake and I use it as a learning experience. I alienated my team for four games. I was a captain at the time so it made me feel even worse. This year I’m trying to prove to them that I’ve grown up a lot and that’s not me anymore.”

He didn’t allow any quarterback hits and the one time a player got around him occurred when he was late off the ball. The Redskins had gone from a cadence count to a silent snap and Williams admitted he got a late jump. But even then he was able to still protect quarterback Robert Griffin III.

“I’m somewhat proud of myself, but I still feel I could have played better,” Williams said. “I was surprised I was able to go. You guys seen me throughout the week, I wasn’t looking very well. I could play a lot better. But I was surprised I was able to be out there.”

Williams said there was never a point he felt like he needed to leave the game, saying he had come too far to think that way.

“There were a couple times where I felt like maybe I could have executed that block better with two healthy knees,” he said.

Williams has played well in the first four games, though he deferred judgment on his season to others. His goal is to someday unseat Eagles left tackle Jason Peters (out for the season with an Achilles injury) as the best player at this position.

“I wouldn’t strip the title from him just yet,” Williams said. “He’s what everyone should be shooting for. I know that’s what I am.”