Mike Singletary's plan for two-a-day practices in full pads from the get-go has his players just a bit nervous heading into the coach's first training camp in charge of the San Francisco 49ers.

"That's tough, man, teeheehoo," linebacker Takeo Spikes said, exaggerating his sigh. "To know you're having that much contact on a consistent basis, you open yourself up to some things, injuries, stuff we don't want to talk about but that's the reality of it. At the same time you have to get your work done, but we just have to be smart about it."

Spikes began training twice a day five weeks ahead of time rather than his typical two weeks, calling it "the best I've ever had since I've been in the league." Left tackle Joe Staley and the rest of the offensive linemen seriously took their workouts up a notch, too.

"Ready for it to be over," Spikes joked Thursday, when veteran players reported to the team's training complex in advance of the first practice Saturday.

That's when the real grind begins. There's no day off in the practice schedule before the team's exhibition opener Aug. 14 at home against the Denver Broncos.

"I expect it to be physical and intense with a lot of competition," said Staley, recently rewarded with a six-year contract extension. "If you know Singletary, he's known for his intensity. ... I feel as strong as I've ever felt in my career."

"I want winners," screams a billboard just up the freeway from team headquarters, featuring a picture of a serious Singletary with arms crossed.

"What I expect from Coach Singletary is we're going to hit the ground running," Spikes said. "I'm pretty sure he wants to see who is going to be all in and who's going to be his players as far as stepping up to the plate not only when it's time for you to do it when you're fresh but as these weeks go on."

Linebacker Parys Haralson cradled the thick, spiral-bound defensive playbook _ "DEFENSE 2009" _ under his left arm as he made his way to the lunch tent on a breezy, 78-degree afternoon, when a rabbit scurried across the nearby field turf.

In April, Haralson received a four-year extension through 2013 after emerging as the 49ers' top pass-rusher last season, getting eight sacks despite playing only sparingly in the season's early games. The former fifth-round pick finished fifth among NFL linebackers in sacks.

Also Thursday, the 49ers signed defensive lineman and former Stanford star Babatunde Oshinowo to a one-year deal. He gives San Francisco depth while Ray McDonald and Ricky Jean-Francois are out of practice with minor injuries.

Oshinowo spent 2008 on the Philadelphia Eagles practice squad. He signed with the Carolina Panthers on January 28 this year but was released on June 26.

The Niners were set for their first team meeting Thursday night, followed by position meetings, then more of the same all day Friday.

"A lot of meetings," said Staley, who plans to assume a greater leadership role in 2009.

The team took a big hit Wednesday, when San Francisco placed cornerback Walt Harris on injured reserve two months after surgery on his right knee put the former Pro Bowl player's career in jeopardy.

Harris tore a ligament in his knee during minicamp workouts on May 19 in a collision with receiver Dominique Zeigler.

What about rookie wide receiver Michael Crabtree, who could be a holdout come Saturday if he doesn't sign soon.

"Nothing right now," 49ers general manager Scot McCloughan said.

The record-setting receiver from Texas Tech was the 10th overall pick in the NFL draft by San Francisco after he unexpectedly slipped several slots on draft day.

His teammates hope Crabtree shows up soon.

"We'd like to have him right now," Staley said. "Business is business. He's got to do what he's got to do on his end."

Added Spikes, "Well, he's behind, that's the obvious thing."

Singletary, beginning his first full season as head coach after taking over for the fired Mike Nolan last October, is overhauling the 49ers' offense with a philosophy heavily committed to the running game. San Francisco went 7-9 last season and scored only 339 points.

"We made no secrets we're going to be a running team," Staley said. "It's not a boring playbook at all. I think we're going to be a very balanced offense."