Notes from today’s practice

Impostor linebackers, Hall of Fame defensive backs and other notes from today’s voluntary practice in Santa Clara…

• The 49ers practiced third-and-long plays on the short end of the field today, with the defense in nickel coverage. That led to some interesting formations. The defense frequently lined up just two D-linemen (Ray McDonald and Justin Smith with the first team), flanked by two outside linebackers, with two inside backers behind them. On some plays, the OLBs had their hands on the ground while the DTs were standing and showing rush. S Michael Lewis manned one of the ILB positions for a while.

• Hall of Fame defensive back Rod Woodson, who played for the 49ers in 1997, watched practice with a camera crew from NFL Network. His interview with QB Alex Smith will appear on the network’s “Total Access” show this evening.
• David Carr was probably the most accurate of the 49ers’ quarterbacks today, in just about every segment of practice. He hit TE Vernon Davis and WR Dominique Zeigler, among others, in traffic. Alex Smith was a little less consistent, but made a perfect downfield throw to RB Glen Coffee to beat LB Matt Wilhelm, and another to TE Joe Jon Finley at the goal line.
• Anthony Davis and G Mike Iupati continue to get double duty with first- and second-team O-lines. Iupati: “It feels great. I’ve just got to get better.”
• WR Brandon Jones turned an ankle and missed a little time. He didn’t join Ted Ginn, Kyle Williams and LeRoy Vann for kickoff returns; not sure if it was because of the ankle. Jones dropped a pass from Alex Smith before the ankle twist, then came back to catch a TD pass from Carr on a skinny post.
• First-team nickel defense had Karl Paymah and Keith Smith at the corners, Tarell Brown inside in the slot.
• Interesting day for LB Martail Burnett: He came up limping after one play, got barked at colorfully by defensive coordinator Greg Manusky, and beat high-profile rookie T Anthony Davis on a pass rush.
• Noteworthy plays by CB LeRoy Vann (in great position on two passes), S Curtis Taylor (a couple pass breakups, one in the end zone), WR Jason Hill (came back for a pass and got his feet inbounds at sideline), S Taylor Mays (knocked away Alex Smith’s pass in end zone), and DTs Derek Walker, DT Justin Smith and Khalif Mitchell (QB pressures).