Robert Saleh explains how K’Waun Williams impacts the whole 49ers defense

Cornerback K'Waun Williams is one of many San Francisco 49ers players slated to hit free agency after this season. He has proven to be one of the best slot corners in the league and a vital part of defensive coordinator Robert Saleh's defense.

Saleh spoke with reporters on Thursday. He discussed Williams and how the cornerback's ability to quickly dissect what is happening on the field has a ripple effect on his teammates.

"The nickel position, in our scheme, we want our guys to go as fast as humanly possible," Saleh said. "The faster you go, the faster you clear it up for other people. So, with [Williams] and with all his preparation that he goes through and his instincts and understanding of football, when he makes a decision, there is no gray area in how he reacts. Because of it, it is very easy for players to play off one another. They feel color, they feel him going. He clears up the picture. It's when players are what we call floating that it just muddies up because you just can't feel where he is and what he's about to do.

"The reason why everyone loves [Williams] is, especially yours truly, the speed at which he operates and the instincts and the trigger — we call it trigger — and the way he triggers on game day. And within each play, it clears everything up for everybody."

Williams' savviness and quick decision making grant him some flexibility when it comes to what is expected of him.

"We allow [Williams] to do some things that are not in our playbook because we know he's going to go a hundred miles an hour and if he can, like I said, it clears it up," Saleh continued. "The nickel spot probably is one of the more important spots on our team, just because of the fact that it does, it clears up a lot of people. ... [Williams], when he's in there, because he is uniquely good at that nickel spot, he does clean it up for a lot of the guys."

Tarvarius Moore was asked how Williams' disruptiveness impacts his own play at the safety position.

"He definitely helps us out a lot when he's in the mix, down there in the box, just being disruptive, or shooting his shot in the gaps, and just cleaning up the run for us," Moore said. "What he does in coverage, gets hands on guys, rerouting them, making them go over the top, just clearing up the reads for us in the back end.

"He's phenomenal at what he does, so we always just show our appreciation to him and what he does each and every week."