SAN DIEGO -- Adrian Gonzalez received a rare day off on Wednesday against the Rockies, as he was left out of the starting lineup for just the third time this season.

Padres manager Bud Black said the combination of a day game after a night game and the fact that Gonzalez aggravated his right shoulder on Monday were the reasons he decided to give Gonzalez a breather with Rockies' left-handed starter Jeff Francis on the mound.

Gonzalez had started 74 of the Padres' 77 games at first base entering Wednesday.

"[We'll] let [the shoulder] quiet down against a lefty, where we have an opportunity to get our right-handed bats in there," Black said.

Oscar Salazar made his second start of the season at first base in Gonzalez's place. Salazar also started at first last week against the Rays, when Gonzalez served as the designated hitter.

Gonzalez being omitted from the starting lineup was one of a few tweaks for the Padres on Wednesday, as regulars David Eckstein and Tony Gwynn also got the day off. Jerry Hairston Jr. started at second base and hit leadoff and Chris Denorfia got the start in center field and hit in the No. 2 hole.

Simmons sees growth from Hundley

SAN DIEGO -- Be careful what you wish for when you ask San Diego bench coach Ted Simmons about the progress catcher Nick Hundley has made.

Simmons, who was an eight-time All-Star, catching 1,771 games during a 20-year Major League career, doesn't have an easy, off-the-cuff answer.

It's much more complicated than that.

The short answer: "1,500 at-bats or 500 games ... that's when you know if you have got an everyday, big league catcher," Simmons said. "Or if you have a backup or a marginal platoon guy."

Simmons has seen growth in the past year and a half he's been working with Hundley -- who entering Wednesday's game against the Rockies, has 611 career at-bats and 176 games behind the plate.

But Simmons isn't ready to give a complete grade yet, even though he's seen some very good things on the defensive end from Hundley.

"There's no question that he is growing. We are all seeing wonderful progress. When I first came here last year, everything he did was in fast motion. ... Everything that was thrown to him, he caught, tried to transfer and throw in what looked like fast motion," Simmons said.

"He has slowed down considerably."

The Padres want Hundley to be quick, but not fast, with his defensive mechanics. They have seen inroads toward that end, even as recently on their 5-1 road trip to St. Petersburg and Florida last week.

"I've tried to slow down and be smoother, be calmer," Hundley said. "Teddy and I have worked tirelessly on slowing it down and working on mechanics."

On that trip, Hundley threw out three baserunners in critical situations. All told, Hundley has thrown out eight of 34 would-be basestealers (23.5 percent). A year ago, Hundley was 10 of 66 (15.2 percent).

Simmons said he's seeing a much better prepared catcher, someone who is getting more comfortable with the league and opposing hitters and baserunners. That information has led Hundley to build what Simmons calls a database.

"All that fast motion comes from uncertainty -- who is this hitter, what does he like, what pitches does he like, not like, who is the pitcher, what does he throw and what pitches can he command? All of those anxieties create uncertainties, especially with young catchers because there's so much that has to be crammed in," Simmons said.

"You're seeing a much more comfortable defensive player now, someone who is learning the hitters, who knows his pitchers. He's incorporating all this data in his database so that in action, he can draw on it and draw on it quickly."

Venable remains out with back stiffness

SAN DIEGO -- Padres right fielder Will Venable was out of the starting lineup for the second consecutive game on Wednesday against the Rockies because of lower back stiffness.

Venable received treatment for the injury prior to Wednesday's game, and Padres manager Bud Black said Venable could be available as a pinch-hitter or defensive replacement if he continues to progress throughout the day.

Black said Venable likely would not have started Wednesday's game anyway because left-hander Jeff Francis was on the mound for the Rockies, but Black is hopeful Venable will be ready to play on Thursday against the Astros.

Venable, who has started 53 games in right field for the Padres this season, said the injury first popped up during Monday's game but that he really felt it when he was lifting weights following the contest.

"After the game, [while I was] lifting, it just kind of spazzed up a little bit," Venable said. "We calmed it down a little bit, but we're kind of just being cautious with it."

Venable is batting .242 this season, but has nine hits in his past 26 at-bats, including four home runs.

Aaron Cunningham made his fourth start of the season in right field for San Diego on Wednesday and batted seventh. Jerry Hairston Jr. started in right on Tuesday and went 1-for-4 with a solo home run.

Black celebrates 53rd birthday on Wednesday

SAN DIEGO -- Padres manager Bud Black turned 53 on Wednesday and you can bet that he was hoping to celebrate it with a victory over the Rockies at PETCO Park.

Black, in his fourth season as manager, is 3-0 when the Padres have played games on his birthday.

The Padres have defeated the Dodgers (2007), Rockies (2008) and the Astros (2009) on his three previous birthdays.

Black was born on June 30, 1957 in San Mateo, Calif.