SAN FRANCISCO -- The Giants essentially finalized their pitching staff, including their sometimes embattled bullpen, by demoting four right-handers after Saturday's 6-4 exhibition loss to the Oakland A's.

Scott Munter and Brian Wilson were optioned to Triple-A Fresno, and Scott Atchison and Sun-Woo Kim were reassigned to Minor League camp. All had been candidates for relief spots. Infielder Tomas De La Rosa also was reassigned to Minor League camp, trimming the roster to 29 players.

The Giants thus will enter the season with right-handers Armando Benitez, Vinnie Chulk, Kevin Correia and Brad Hennessey and left-handers Steve Kline, Jonathan Sanchez and Jack Taschner.

The decisions were difficult, largely because most relievers performed erratically. Manager Bruce Bochy said that he and the rest of the Giants' braintrust discussed the composition of the bullpen daily.

"It was a very tough call," Bochy said. "But when you look at the rest of the guys, we felt these were the best guys to break with."

Wilson began Spring Training as a legitimate candidate to wrest the closer's role from Benitez, but recorded a 7.71 ERA in a team-high 13 appearances. Perhaps worse, he walked seven in 11 2/3 innings.

"We still see him as [having] closer potential," Bochy said. "We just think at this point, it's best for Brian and the club if he gets some more work in. ... It's [to develop] consistency in the whole game."

The Giants still must cut four players by noon PT on Sunday. Since the Giants are likely to stick with a 12-man pitching staff -- "There is a very minute possibility we could change that," Bochy said -- only one spot will be open for veteran reserves Jason Ellison, Lance Niekro and Mark Sweeney. Ellison and Niekro are out of Minor League options, so they can't be sent to Triple-A without being offered to other clubs through waivers first.

First things first: The top of the order topped the Giants' list of bright spots against the A's.

Leadoff batter Dave Roberts and No. 2 hitter Omar Vizquel demonstrated how artful and effective they can be in combining to stimulate the Giants' offense.

Roberts doubled in the first inning and moved to third on Vizquel's grounder to first base -- a "productive out" that drew cheers from the cognoscenti in the AT&T Park crowd. Vizquel's effort indeed proved useful, because Ryan Klesko's sacrifice fly scored Roberts.

The collaboration worked again in the third inning, which Roberts christened with a single. He stole second base and scored on Vizquel's single. Vizquel also stole second, but languished there.

"Hopefully I can feed off him and he can feed off me," Roberts said.

Roberts and Vizquel might have done even more, except they were out of the game by the fifth inning.

Accustomed to Vizquel's handiwork, the Giants are thrilled that Roberts can complement him.

"I think he's a tremendous asset," right-hander Matt Morris said. "He's a guy, in a good way, who's just really annoying and pesky. He's a guy you want on your team, not a guy you want to face. Whether you get him out or he gets a hit, it's 20 pitches into the at-bat. He's not giving anything away. He battles on every pitch."

Benitez back-to-back: Benitez said that he was "a little stiff," but otherwise felt good one day after appearing in his second consecutive game, a prerequisite for any reliever approaching the regular season.

As the Giants' closer, Benitez knows that Bochy might call upon him more than just two days in a row. Asked if he believed he could pitch for longer stretches, Benitez replied, "It depends on how I feel. ... If I'm ready, he can use me every day."

After blowing 12 saves in 48 chances in two seasons with the Giants, Benitez appears to be on the brink of a significant turnaround, recording a 0.96 ERA in nine exhibition outings. This has virtually silenced trade talk involving Benitez. But as a 12-year veteran who has been traded three times, he won't assume anything.

"You never know. Nothing surprises me," Benitez said. "It [depends on] what the Giants want to do."

The right-hander declined to discuss the subject further, saying, "I just want to do my job and help the team."

Bruins pride: Roberts literally showed his colors Saturday. As his alma mater, UCLA, prepared to face Florida in the Final Four semifinals, Roberts showed up at AT&T Park wearing a Bruins cap, T-shirt and windbreaker. His dressing stall had almost as much blue-and-gold as black-and-orange.

"It's a big day, suffice it to say," said Roberts, who spoke glowingly of UCLA basketball's "legacy and prestige." He added, "There's a sense of pride, without a doubt."

Roberts barely missed an opportunity to root the Bruins toward a national championship as a collegian. They won their last one in 1995, a year after he left school.

"I was making the big bucks in 'A' ball -- $950 a month," he recalled.

Coming up: The Bay Bridge Series ends Sunday, and with it the exhibition season, when the Giants visit Oakland's McAfee Coliseum. With final roster cuts due, it'll be a tense day for several players.