Eric Mangini is planning on putting his own mark on the San Francisco 49ers' 3-4 defense with that being total confusion.

"All D-coordinators have their style," 49ers safety Antoine Bethea said, via peCSN Bay Area. "Coach Mangini, his thing is we're going to cause confusion. The opposing offense isn't going to know what we're going to be able to do each down. It could be bringing the pressure. It could be dropping eight into coverage. But it's just keeping the offense on their heels. However, you want to look at it, I think it's going to be a good deal for our defense."

Vic Fangio built one of the NFL's best defensive units from 2011 until 2014.

Ray McDonald has been arrested on a domestic violence charge in the San Jose area.

The exact date and nature of the alleged incident was not immediately spelled out. 

McDonald signed with the Chicago Bears this offseason and has been released following the incident.

Last season, McDonald had two domestic incidents requiring police attention and was also named a suspect in a sexual assault investigation.

Reggie Bush would like to return punts again this season.

Bush hasn't returned any punts since 2011, but he's taken four back for touchdowns during his career, plus one more in the playoffs.

“It was my idea,” Bush said, per CSNBayArea.com. “I told the coaches I wanted to return punts again. And they were excited about it. We're still working at it, still chipping away. And we look forward to being an all-around great special teams.”

Justin Smith has decided to retire from the NFL after 14 seasons.

Smith was a five-time Pro Bowler.

Sith was selected as the fourth overall pick by the Cincinnati Bengals in the 2001 NFL Draft and had his biggest success anchoring the San Francisco 49ers' defense that played in three straight NFC Championship Games.

NaVorro Bowman hasn't played since injuring his knee in the 2013 NFC Championship Game, but he returned to practice late last month.

"Bowman's looking great," Jim Tomsula said, via Matt Maiocco of CSN Bay Area. "Bow looks great. I'd say we're more treating Bow like a vet than we're treating Bow like a post-injury guy right now."

The San Francisco 49ers lost Patrick Willis and Chris Borland to retirement in the offseason and will need Bowman to be productive.

Trent Baalke expects to meet with Justin Smith this week about his future with the San Francisco 49ers.

Smith continues to consider retirement as he would be playing his 15th NFL season if he does return.

The 49ers have not even ruled out a mid-season return for Smith, if he is not willing to commit at this time to playing the 2015 season.