SANTA CLARA, Calif. — If there were any doubts about the type of offense Mike Singletary and the 49ers will run this season, they were swept away — no, stomped away — Thursday evening.

Fearing that the offensive tackle they coveted and badly needed would be stolen in front of their eyes, the 49ers traded up two places to snag Anthony Davis, a 323-pound junior tackle from Rutgers. Six picks later, they added even more beef to their offensive line with 331-pound Idaho guard Mike Iupati.

That's 654 pounds of power-blocking offensive linemen added in less than an hour. Davis will line up at right tackle; Iupati at left guard, the position he played with the Vandals. Singletary cautioned that both players might not start in Week 1 — Davis is one of the youngest players in the draft at age 20 but he made it clear he expected both to start at some point this season.

Iupati was selected with the No. 17 pick. That's the earliest a pure guard has been taken since Seattle drafted Steve Hutchinson, a seven-time pro bowl selection, in 2001. Singletary said he had no concern that Iupati was taken too early.

"This guy's a devastating, physical blocker," Singletary said. "Both of these guys are. Iupati — he's extremely physical. It's going to be quite interesting. (Offensive line coach) Mike Solari and (assistant) Ray Brown are very excited about getting their hands on both these young men and being able to work with them."

Acting general manager Trent Baalke was manning the phones for the 49ers and orchestrated the trade that secured Davis. At the conclusion of the first round, an ebullient Baalke walked into the interview room looking like a man who had just hauled in a 1,000-pound tuna.

"We targeted these two players," Baalke said. "And we said, 'You know what, if we come out of the first round like this, it would be the perfect storm.' We feel good."

The two picks give Singletary precisely the type of big-bodied, physical offensive line he's been pining for since he became head coach.

A year ago, Singletary wanted to draft "The Blind Side" offensive tackle Michael Oher, but capitulated when receiver Michael Crabtree unexpectedly fell to the 49ers at pick No. 10. This time, Singletary and Baalke grabbed the player who has drawn the closest comparisons to Oher, who started 16 games at right tackle last year for the Ravens.

The 49ers drafted Crabtree in 2009 when the Raiders passed on him three picks earlier. Oakland again figured in the 49ers' draft. When the Raiders selected linebacker Rolando McClain with the No. 8 pick, the 49ers knew they had a good shot at Davis. Baalke said he knew the two teams picking in front of the 49ers, Denver and Miami, didn't need an offensive tackle. But there were other teams lurking — the Cowboys and Packers — that also wanted to add to their offensive line.

"I wasn't concerned, worried about the teams in front of us at all," Baalke said. "I was more concerned about who else may come up and jump ahead of us because they knew what are needs were at the time."

So Baalke began making phone calls, first with Jacksonville, which had pick No. 10, and then with the Broncos at pick No. 11. The 49ers and Broncos swapped first-round picks, and the 49ers also gave Denver their fourth-round selection.

The biggest knock on Davis entering the draft was his commitment to the game.

As a freshman, he arrived at Rutgers weighing 363 pounds — far heavier than what the Scarlet Knights coaches were expecting. He was suspended for a game in 2008 for violating team rules and he also was benched for a quarter the following season for undisclosed reasons.

Singletary, meanwhile, spent the past three months examining the backgrounds of some of the most troubled players in the draft. Singletary was far more active than any other head coach, traveling from coast to coast to watch players work out for scouts.

Singletary said he had comprehensive interviews with three people close to Davis. He also had dinner with Davis last month, an encounter that left Davis hoping he'd land in San Francisco.

Singletary called Davis to tell him he was the 49ers' pick. And what did the coach say he expects of Davis?

"To work," Davis said. "To want to be the best. And that's what he got. He got somebody who wants to be the best."