The Kansas City Royals stood by Zack Greinke. Now, Greinke is standing by them.

Delaying a chance to make even more money as a free agent, the right-hander agreed Monday to a $38 million, four-year contract that avoided a salary-arbitration hearing.

Greinke, the No. 6 overall draft pick in 2002, was rushed to the majors because the Royals were desperate for talent. Often moody and uncommunicative, he suddenly bolted from spring training in 2006 and went home to Orlando, Fla., thinking he was probably through with baseball.

But the Royals talked him into seeking treatment for what was diagnosed as social disorder. Former general manager Allard Baird and ex-manager Buddy Bell spent countless hours with their discouraged young pitcher, who, in his own words, “just hated being around people.”

Greinke admits it was a struggle. But by 2007, he was back in the big leagues to stay. With a lively, biting fastball and good command of three other pitches, he went 13-10 in 32 starts last year, setting career highs in strikeouts (183) and innings (202 1/3). His 3.47 earned-run average was the best by a full-time Royals starter in 11 years.

“It was awesome. They could’ve easily pushed me aside, or helped me get back and then dump me off as soon as they could get something for me,” Greinke said. “But they did everything they could, bent over backwards to help me.”

The 25-year-old Greinke, just coming into his prime earning years, could have become a free agent after the 2010 season.

“He may have been the most sought-after free agent in the winter of 2010,” general manager Dayton Moore said. “We went aggressive with Zack, and fortunately we got the backing (from ownership) to be able to do this.”