Compared with most major league contracts, filled with escalator clauses and incentive packages, Chase Utley's deal in the off-season was pretty basic. He did not need an agent to negotiate the terms. He did not need a lawyer to dissect the language. He needed only a clear conscience and a ballpoint pen.

The contract is 182 words, but it boils down to one sentence: "I pledge that I am not using any illegal or unethical performance-enhancing drugs."

Utley read and signed the document, without any haggling or soul-searching. "For me, it was no problem," he said last week in Philadelphia.. "It was no big deal."

Utley, the Phillies' lanky second baseman, was not trying to make a grand statement. He was just trying to go work out. Every off-season, when Utley enrolls at Athletes' Performance, a training center with branches in Southern California and Arizona, he has to sign the contract. Anyone who enrolls must do the same.

Considering how many baseball players have said that they do not take steroids — and how many have then been suspended for doing steroids — the pledge can seem hollow. After all, Athletes' Performance does not give drug tests and revokes a player's membership only if he is later exposed as an offender.

But in today's climate, with seemingly all major leaguers under suspicion and their trainers under scrutiny, even the simplest gesture condemning steroids is significant. With obvious gaps in the drug-testing program, baseball must hope that its players adhere to their own personal honor code.

When Utley talks about his off-season regimen, he makes the pledge sound like the easiest part. He spent more than an hour a day doing agility drills on a soccer field and another hour lifting weights. Utley, who is batting .295 with 12 homers after the Phillies' 4-2 victory over the Yankees last night, is increasingly referred to as the best second baseman in the majors.

Although Utley showed up to spring training this year looking a little bulkier than usual, few people questioned him because they remembered where he had been. Athletes' Performance, with 75 major leaguers on its roster, has become known around baseball as the place with the pledge.

"This has acted as the foundation to our entire company vision," Mark Verstegen, the president and founder of Athletes' Performance, wrote in an e-mail message.

Such codes of conduct are common in high school and college athletic programs, but they were traditionally considered unnecessary for professionals. With the proliferation of performance-enhancing drugs in major sports, however, training centers are taking less for granted. "What's new is that elite sports-performance facilities are catching on," said Al Green of the National Athletic Trainers' Association. "I don't know how much of it is because of Barry Bonds and Balco. In a way, the business wants to protect itself as well as make sure the athletes are training the right way."

Utley, one of the prized pupils from Athletes' Performance, is baseball's version of a late bloomer, a 27-year-old who won a full-time job in the major leagues last season and started playing second base only at Class AAA. His swing, an exercise in compact efficiency, has set him apart from a legion of singles-hitting second basemen.

He has an open stance, adopted after years of watching Jim Thome, first on television as a fan, then from the dugout as a teammate. He prepares for each pitch by tapping his back shoulder with his bat. Then he attacks the ball as if it has wronged him. Although most sluggers have a long and dramatic follow-through, Utley ends his swing shortly after contact, as if he were a golfer punching chip shots off the right-center-field fence.

"That's great wrist," said Milt Thompson, the Phillies' hitting coach. "People don't understand; they think you need brute strength to hit a ball a long way. He just squares it up and uses those wrists."

Before Utley was building his wrists at Athletes' Performance, he was training at the Lakewood Batting Cages in Lakewood, Calif., a lower-profile facility. When he was in elementary school, his parents dropped him off at the neighborhood batting cages with a pocket full of quarters, and he hit until the money ran out.

"Then we'd let him sweep the floors so he could make enough money to hit some more," said Kevin Tyler, owner of the Lakewood Batting Cages. "He started here on the 35-mile-per-hour machine and went through the 80's."

Among those hitting alongside Utley were Milton Bradley, Jason Kendall, Jay Gibbons and Sean Burroughs, other Lakewood products who made it to the major leagues. Utley's high school, Long Beach Polytechnic, had an even more distinguished alumni list. The school's most famous rapper is Snoop Dogg, its most famous movie star is Cameron Diaz and its most famous baseball player is Tony Gwynn.

Utley, with his own lofty ambitions, was the rare player to turn down a professional contract after he was drafted in the second round out of high school. He went to U.C.L.A., eventually became a first-round pick of the Phillies and quickly won recognition in the minor leagues for challenging teammates and bowling over catchers.

"He was really vocal," said Ryan Madson, a Phillies pitcher who played with Utley at Class A and Class AAA. "He was the leader on every team in the minors. He's a lot quieter now, but I think that will change. He will be the leader here, too."

When the Phillies are playing well, their identity matches Utley's personality. He is the type who shows up early and leaves late, chats up teammates but avoids television cameras, and never considers his day complete until his uniform is stained. "He's a throwback guy," said Pat Gillick, the Philadelphia general manager. "He doesn't leave anything for tomorrow."

Just as the Mets are building a future around the left side of their infield — third baseman David Wright and shortstop José Reyes — the Phillies are building around their right side, with Utley at second base and Ryan Howard at first. Howard is a hulking power hitter who has long been pegged for stardom, but Utley needed more time, and maybe a few more off-season workouts, to realize his potential.

"Chase has a ton of natural ability, but I do think the things he did in the winter have helped him express his game," said Vasso Chronis, the coach who worked with Utley at Athletes' Performance. "I love seeing him do well right now because I know how hard he worked, and because I know everything we did together is ethical."