SAN FRANCISCO -- A day after watching pitcher Anthony Bass retire the first 17 Giants hitters he faced, Padres manager Bud Black was still raving about Bass' performance at AT&T Park.

More than that, though, Black said he has been impressed with the improvements Bass has made since he first appeared in the big leagues with the team last season.

"It's more than a tick better. ... I would say he's much improved in a lot of areas," Black said.

Bass used a three-pitch mix -- fastball, slider and changeup -- to tie the Giants' hitters in knots as he took a perfect game into the sixth inning. Tim Lincecum broke up the no-no with a two-out single. The Giants then scored twice in the seventh inning on their way to a 2-1 victory.

Bass allowed two runs on six hits with no walks as he tossed a career-high eight innings and also set a new career best with eight strikeouts.

"He's evolved from throwing to a pitcher," said Padres catcher Nick Hundley. "He was a guy who first would rear back and throw it to a pitcher, a guy who is using all of his pitches. He's quickly improving."

Last season, Bass made three starts and had a total of 27 appearances in two stints with the team, as he posted a 1.68 ERA. This season, he has a 2.30 ERA in six games, including four starts since he moved into the starting rotation earlier this month.

"He's quieted down his delivery and that's helped him make more consistent pitches," Black said. "It's just a maturation process and he's learning it on the job."

In a combined 75 2/3 innings in his short Major League career, Bass has a 1.90 ERA in 33 games, seven of which have been starts. He's allowed 59 hits and 31 walks and has 51 strikeouts in that span.

Stauffer pitches in first rehab start

SAN FRANCISCO -- Pitcher Tim Stauffer, appearing Sunday for Class A Lake Elsinore on a Minor League rehabilitation assignment, allowed two runs on six hits in 3 2/3 innings.

In a game against Rancho Cucamonga, Stauffer opened with scoreless innings in the first and second inning before allowing a run in each of the third and fourth innings.

This was the first rehab assignment for Stauffer, who went on the disabled list with a strained right elbow on April 5 (retroactive to April 4).

San Diego manager Bud Black said Sunday morning the team would meet with Stauffer in San Diego on Monday but that he would need a second rehab appearance.

"At least two, maybe three," Black said.

Quentin close to starting rehab assignment

SAN FRANCISCO -- San Diego manager Bud Black has been reluctant to lay out a firm timetable for when outfielder Carlos Quentin will go out on a Minor League rehabilitation assignment to test his surgically repaired right knee.

On Sunday, Black had more of a definitive answer.

"It might be middle of the week," Black said. "It's nearing."

Quentin had a rigorous day going through normal baseball activities before Saturday's game against the Giants. He was set for a slower day Sunday before he gets another full day of work Monday when the team returns to Petco Park.

"He's still got to run the bases and do more intensive fielding drills. Hitting, he feels fine. We're trying to get him up to speed as soon as we can," Black said.

Quentin had arthroscopic surgery on the knee on March 19. He's had no setbacks to this point during his rehabilitation.

Black said Quentin will either play for Triple-A Tucson or Class A Lake Elsinore and will first serve as the designated hitter before eventually moving into the field.