SANTA CLARA The 49ers are rolling in reinforcements for a pass rush that sagged at the end of the 2012 season.
The team used the first of two second-round picks Friday on Florida State defensive lineman Cornellius Carradine and a third-round pick on Auburn's Corey Lemonier, who will play outside linebacker for the 49ers.
Carradine is known to friends, family and fans as "Tank."
"When I was a kid, I had this little army tank always with me," he explained from his home in Cincinnati. "I could never go anywhere without that army tank. I just had to have it with me, and I used to always push people over, try to run over people and always had my army tank with me.
"So, that's how I got the nickname Tank."
The 49ers hope Carradine takes the same direct approach against offensive lines.
General manager Trent Baalke said he envisions the 273-pounder bulking up in coming seasons and playing defensive end in San Francisco's 3-4 defense.
He also could be a hand-on-the-ground rusher in passing situations.
That makes him the likely heir to Justin Smith, whose late-season arm injury in 2012 showed how critical a quality right defensive end is to the 49ers' defense. Smith turns 34 early next season and is entering the final year of his contract.
The bigger question for Carradine for the start of 2013, at least is his surgically repaired knee. He tore his right ACL on Nov. 26 and had surgery a week later.
Last week, the 49ers sent defensive-line coach Jim Tomsula to Cincinnati to meet Carradine. The two dined together Friday night, then Tomsula watched the defensive lineman go through football drills.
Carradine ran the 40-yard dash in 4.75 seconds, fast for any defensive lineman, much less one who had ACL surgery 135 days earlier.
"I'm doing just as much as anybody that's nine or 10 months out (from surgery)," said Carradine, who rehabilitated at the same Houston facility where Vikings running back Adrian Peterson worked last year.
"It goes along with all the work ethic," Carradine said. "It's just genetics and the guys that I rehab with, and we all put it together and worked on it, and we got the knee back together."
Baalke said he and the team's medical staff went over Carradine's injury on Thursday and that his prognosis was good. Still, Baalke wouldn't say when Carradine was expected to be ready to play.
"That remains to be seen," he said. " The time frame that's really up to the medical staff."
Lemonier, meanwhile, joins a packed house at outside linebacker. On the roster are starters Aldon Smith and Ahmad Brooks and reserves Parys Haralson, Darius Fleming and Cam Johnson. Aside from Brooks, each had some sort of surgery before or in Smith's case after the season.
"We've got a good group of linebackers, and he's going to have to come in and earn his position," Baalke said of Lemonier.
For the second straight day, the 49ers used their draft haul to maneuver up and down the board. They traded back in the second round to get Carradine and up in the second and third rounds to get Rice tight end Vance McDonald and Lemonier, respectively.
McDonald will replace Delanie Walker, who left via free agency to Tennessee. Walker was a college wideout, and McDonald spent his junior season playing slot receiver for the Owls. He played a more traditional tight end role this past season.
"He's played on the line of scrimmage, and he's a much bigger man," Baalke said of the comparison with Walker. "Delanie was a shade over 6-2 and roughly 240 pounds coming out of college. This guy's a little over 6-4 and 265-plus pounds coming out.
"So there's a considerable size difference, and there's a bigger body of work."
The 49ers have seven picks remaining today.