Pollok, 27, has compiled a 2-0 record with a 1.78 ERA -- the second lowest on the staff behind Mike Koplove's 0.93 -- in 10 games, scattering 18 hits in 25 1/3 innings, with one walk and 14 strikeouts.

After allowing four earned runs in seven innings in his first two outings, Pollok has allowed only one run in 18 1/3 innings in his last eight appearances.

"He's been a savior for our staff," 51s pitching coach Jim Slaton said. "We had some starting pitchers who have struggled, especially early in the season, and he's come in and picked up a lot of innings for us. He's been very consistent.

"He pounds the bottom of the strike zone and gets a lot of ground balls, and he's done a fantastic job for us so far."

Pollok, in his sixth professional season, was traded to the Los Angeles Dodgers in May 2007 from the Chicago White Sox for infielder Tomas Perez.

Pollok started last year with Charlotte of the International League, going 1-1 with a 3.33 ERA in 18 games, and finished the season with the 51s, going 1-2 with a career-high 5.71 ERA in 28 games, including his first five pro starts.

"I was just trying to get settled in here last year. It was tough to get comfortable," the affable Pollok said. "But going through spring training this year and getting comfortable with being a Dodger helped out a lot with staying focused."

Pollok wasn't on the active list for Las Vegas (17-16) when the season started. But when Chan Ho Park was called up to Los Angeles on the eve of his scheduled Opening Day start for the 51s, Pollok was pressed into action.

"We talk about opportunity all the time, and here's a young man who has taken advantage of an opportunity," Las Vegas manager Lorenzo Bundy said. "He stepped up and really saved us, especially the first few weeks. We had trouble with our starters getting deep into games, and he picked us up every time."

A Texas native who pitched at Texas A&M, Pollok was drafted by the White Sox in the 27th round in 2003 and rose rapidly through their system, recording a Class-A franchise-record 38 saves in 2004, when his slider was rated the best in the White Sox organization.

Pollok, who entered this year with a 3.65 ERA in 239 minor league games, has added more than 5 pounds of muscle through a strict offseason workout regimen. Another key to his success has been the development of his sinker, a pitch he didn't throw until last year that now is his best one.

"It was a big part of my game last year, and it's an even bigger part this year," Pollok said. "I've never seen a ground ball go out of the park."