SAN FRANCISCO — The San Francisco Giants added a much-needed catcher to their system today, selecting Florida State's Buster Posey with the fifth pick in the draft.

He's also an offensive threat who the club believes could quickly contribute in the majors. That might even be in the next couple of years considering starter Bengie Molina's contract is up after the 2009 season.

"He's going to have impact both ways, defensively and with the bat, in a hurry," general manager Brian Sabean said. "He's on the fast track and Bengie's clock is winding down. It's really up to him how soon he wants to get going and how soon he can get here. ... We were looking for the best all-around player."

San Francisco wasn't sure Posey would still be available at No. 5 because several other teams picking higher also had interest, but also had Vanderbilt third baseman Pedro Alvarez on their board if he was still around. Alvarez went to Pittsburgh with the second pick.

The Giants have shown they aren't afraid to bring up young players to the big leagues. Right-hander Tim Lincecum was the team's 10th overall selection in 2006 and joined the rotation last year.

Sabean sent out one of his top and most trusted advisers, Jack Hiatt, to see Posey and a half-dozen other catchers around the country to get a feel for the talent that was out there.

"He was shocked as to his basic catch-and-throw ability for doing it for a couple of years and was dually impressed with the bat," Sabean said.

Signing Posey could take time as he might command $12 million — but the Giants are prepared to spend the money on a player Sabean assistant John Barr has been high on for years, with the GM saying, "I would expect there's going to be a lot of posturing at the top."

"We're going to work at it. We're not going to put any timetable on it," Barr said. "We're just looking forward to him becoming a Giant."

Posey, whose Seminoles will play Wichita State this weekend in the NCAA Regionals, was drafted as a pitcher and shortstop out of high school by the Los Angeles Angels in the 50th round but headed to college instead. He has a strong arm and his speed is thought of as above-average.

Posey, from Leesburg, Ga., is versatile. He was an All-America shortstop as a freshman then converted last season as a sophomore when Florida State needed someone behind the plate. That alone showed the Giants he is a team player. He also closes games in college.

Last month, the 6-foot-2, 200-pound Posey played all nine defensive positions in one game and hit a grand slam. His strides at the plate helped elevate his status in the draft.

"I think in the draft in general it's a rarity to get an all-around catcher," Sabean said. "He has an upside on both sides of the ball. He can really catch and throw."

The catching position is probably the organization's weakest spot and with the least depth — so this choice certainly fills a big void.

"It's always a need. We lack depth there, especially at the highest level," Sabean said. "We all know Bengie's contract is winding down."

The Giants had their highest draft pick since picking Jason Grilli fourth in 1997. Before that, they took Matt Williams third overall in 1986.

"I had thought highly of this player all along," Barr said. "He was in our consideration for this selection from the day I accepted the position Brian offered me."