It's time, Williams said, Dareus realized he has put his young and promising career in jeopardy after being charged in two separate arrests last month involving drug possession and a car accident.
''I'm hoping that this is kind of a watershed moment for him, because he's at a pivotal point,'' Williams said after Dareus reported for the start of the Bills' three-day mandatory minicamp. ''Hopefully, it's to a point where it's kind of an epiphany, and he comes alive and turns the corner and does his best.''
Williams, a team captain, is taking a tough-love approach with Dareus, a player he's spent the past three years mentoring.
''I think he's heard (advice) from a lot of different levels, whether it be from his teammates or coaches, and I'm sure the front office,'' Williams said. ''So if you can't get it from those three levels, maybe you're not going to get it.''
Dareus, the Bills 2011 first-round draft pick, returned to practice for the first time since he and coach Doug Marrone agreed that the player take two weeks off to sort out his legal problems.
It's unclear what Dareus has been doing during his time away.
The Bills announced before practice that Dareus will not be made available to reporters this week so that he can focus solely on football. Dareus was escorted off the field by a team official following practice.
He's been off since May 30. That's when shortly after participating in a voluntary practice, Dareus crashed his 2012 Jaguar into a tree near a busy suburban Buffalo intersection after allegedly racing teammate Jerry Hughes. Dareus was charged with reckless endangerment and ticketed for several traffic violations, including drag-racing.
Dareus was scheduled to appear at Hamburg Town court on Tuesday, but that was pushed back to July 1 in part so that he didn't miss practice.
Four weeks earlier, Dareus was arrested in his native Alabama and charged with possession of synthetic marijuana and drug paraphernalia.
Rod Giddens, the attorney representing Dareus in Alabama, said he's still awaiting word from prosecutors as to whether they'll accept a plea deal in which Dareus entered a pre-trial intervention program to have the charges reduced or dismissed.
Dareus' troubles actually come from the end of last season when he was benched during each of the Bills final two games because he was late for team meetings.
General manager Doug Whaley intends to meet with Dareus following the Bills' final practice on Thursday, when the team takes a month before opening training camp July 20.
''I'll just have a little sit-down with him when we leave, so everybody's on the same page,'' Whaley told The Associated Press. ''The thing right now is he's back focused straight on football. It's great that he's back. And I think he thrives in a situation like this where it's all football.''
On the field, Dareus returned to his familiar starting spot alongside Williams.
In one team drill during the non-contact practice, Dareus showed off his power and speed by bullying past guard Kraig Urbik to break up a potential pass. On the next play, Dareus spun off Urbik's block and filled the hole to stop a run.
Coach Marrone has stuck by Dareus, while expressing disappointment in saying the player has made ''some poor decisions.''
''I just want to make sure that I'm clear that everyone understands that I believe in Marcell, and I will do everything I can to make sure that we can get him on the right track,'' Marrone said two weeks ago. ''I'm going to do everything I can to help a 24-year-old man make better decisions.''
NOTES: LB Manny Lawson and DL Alan Branch reported for the mandatory minicamp after both skipped the team's voluntary sessions this offseason. Lawson said he found it important to take time off from football and be with his family. ... TE Scott Chandler was excused from practice for personal reasons. Starting LT Cordy Glenn was absent due to an illness. ... Rookie OT Seantrel Henderson missed practice due to travel delays.
AP NFL website: www.pro32.ap.org and www.twitter.com/AP-NFL