SAN DIEGO -- Matt Cain exudes confidence. He has evolved into a team leader. He has a good chance of performing at an All-Star level for a long time.

For that, the Giants can partially thank Dave Roberts.

The end of Roberts' playing career coincided with the beginning of Cain's. That was when Cain received ridiculously low run support. Seeing Cain's talent and concerned that the right-hander might be scarred by the lack of offense, Roberts, a former outfielder who played 166 games for the Giants in 2007-08, took it upon himself to share some of his veteran's perspective with Cain.

Said Roberts, "Everybody could see the potential, but I wanted to impress upon him to be a professional -- don't let the things that are out of your control affect your performance. Take it upon yourself to continue to improve and let the results take care of themselves."

Handling success was one topic Cain recalled. "We talked about when you're going good, sometimes you get worried about, 'When's it going to end?' You can't worry about that," Cain said. "Keep thinking it's not going to end. Just keep doing what you're doing. Keep thinking it can get better and better and if it does end, who cares? That doesn't mean it's going to go bad now."

Cain said that they also discussed off-the-field subjects, such as "ways to carry yourself and treat your family."

Their admiration remains mutual.

"He was just a great person to talk to," Cain said. Their bond as teammates, he added, "is something I think that's always going to carry on."

"I'm very proud of what Matt has done in his career, what he's done in a short period of time and how he has handled success," Roberts said. "That's what makes the game great, when guys like him have success."

Posey has voice back, returns to lineup

SAN DIEGO -- Buster Posey regained his voice and returned to the Giants' lineup at catcher Saturday, one day after being painfully struck in the throat by a one-hop Ryan Vogelsong pitch.

"All in all, I feel good," Posey said in a still-raspy voice. He noted that his throat continued to ache for about three innings after the second-inning incident until the discomfort subsided.

Giants manager Bruce Bochy reiterated that he intends to rest Posey in Sunday's series finale against San Diego. Posey was asked why he's playing at all, with the Giants having clinched the National League West.

"The main thing is to try to stay sharp," said Posey, who entered Saturday leading the NL in batting average (.334) and on-base percentage (.407). "I think we've had some good rhythm going as a team, after we had it handed to us by Arizona in the first game of that series."

Including Saturday, Posey has played in 145 of San Francisco's 158 games, starting 109 behind the plate, 28 at first base and three as a designated hitter.