49ers sticking with 3-4 defense

Despite losing inside linebackers Patrick Willis and Chris Borland to retirement, the San Francisco 49ers have no intention of changing their defensive scheme.

"Yeah, yeah, yeah," head coach Jim Tomsula said Wednesday when asked if the 49ers would still be running a 3-4 defense, according to Matt Maiocco of CSNBayArea.com.

San Francisco still has NaVorro Bowman and Michael Wilhoite at inside linebacker, with Aldon Smith, Ahmad Brooks and Aaron Lynch at outside linebacker.

"You look at the defensive line, the outside linebackers. The depth on the defensive line right now is as deep as we've ever had it," Tomsula said. "I'm real excited about the guys we have there."

Ian Williams and Glenn Dorsey have started primarily at nose tackle, but Tomsula said they could line up anywhere on the 49ers' three-man line. Tomsula is also pleased with the progress of 2013 second-round pick Tank Carradine.

"Tank made a lot of strides," Tomsula said. "He works so hard, and he's talented. Tank came into the NFL, coming off a significant knee injury and making a position change. One of those is tough enough. He had both."

Carradine missed his entire rookie campaign because of a torn ACL and was inactive for several games in 2014. He finished last season with 17 tackles and three sacks.