SAN FRANCISCO -- The Giants began the anticipated revamping of their pitching staff Friday, all but officially severing ties with right-handers Tyler Walker, Kevin Correia and Brad Hennessey.

The trio was outrighted to Triple-A Fresno, along with catcher Eliezer Alfonzo, left-hander Geno Espineli and infielders Scott McClain and Ivan Ochoa. The Giants also activated left-hander Noah Lowry and right-hander Merkin Valdez from the 60-day disabled list and lost second baseman Travis Denker, who was claimed off waivers by the San Diego Padres.

Each of the outrighted players can opt for free agency except for Espineli, who has not been outrighted before and falls one year short of qualifying for six-year Minor League free agency. A Giants spokesman said that the other six have informed club management that they intend to pursue their options in free agency, with the possible exception of Correia.

Regardless, the moves could end the Giants' long associations with Walker -- one of nine native San Franciscans to play for the team -- Correia and Hennessey, who have spent their entire professional careers with the franchise.

Walker, who pitched five seasons with the Giants, began 2008 as one of San Francisco's top setup relievers and threw scoreless ball in 14 of his first 15 appearances, recording a 1.93 ERA. But the right-hander allowed 10 runs in four home games in May, incurring the wrath of AT&T Park fans. By season's end, rookie Sergio Romo became the primary eighth-inning option ahead of Walker, who finished 5-8 with a 4.56 ERA in 65 appearances.

Correia, who had been in the Giants' organization since 2002, entered last season as the No. 5 starter, but strained his left side in April, which limited him to 25 games (19 starts). He finished 3-8 with a 6.05 ERA and was removed from the rotation in late September.

He was replaced by Hennessey, San Francisco's first-round Draft choice in 2001, who opened the year in the Giants' bullpen before being optioned to Fresno on May 7 with a 12.94 ERA in 11 appearances. Hennessey recorded three quality starts in four efforts during the season's final weeks before finishing with a 1-2 record and a 7.81 ERA.

Economics also could have been a factor with Walker, who earned $750,000 last season, Correia ($1.075 million) and Hennessey ($1.6 million). All three were eligible for salary arbitration, and their salaries could not be cut more than 20 percent, under the Basic Agreement.

Denker, among 24 rookies who flooded the Giants' roster in 2008, hit .243 (9-for-37) with four doubles, one triple, one home run and three RBIs in 24 games for San Francisco. He hit .255 in 92 games with Class A San Jose, Double-A Connecticut and Fresno.

McClain (.273, two homers and seven RBIs in 14 games) and Ochoa (.200 in 47 games) both excelled at times for the Giants, but didn't figure prominently into their 2009 plans, although either could be re-signed to provide depth. Espineli sparkled at Triple-A, recording a 2.66 ERA in 38 appearances, and was 2-0 with a 5.06 ERA in 15 games for the Giants.

Alfonzo hit .091 (4-for-44) in Spring Training, lost the backup catching job to Steve Holm and was slapped with a 50-game suspension from the Commissioner's Office for testing positive for a performance-enhancing substance, violating Major League Baseball's Joint Drug Prevention and Treatment Program. He again hit .091 (1-for-11) in a five-game stint for the Giants after his suspension ended before returning to Triple-A.

Lowry, the Giants' leading winner in 2005 and 2007, is recovering from surgery to have a bone spur removed from his left elbow. He missed the entire season after undergoing forearm surgery in March, but is expected to be ready for Spring Training. So is Valdez, who posted a 1.69 ERA in 17 relief appearances before a strained elbow sidelined him in mid-May.

The moves left the Giants' 40-man roster at 33 players.