Kansas City Royals pitcher Sidney Ponson tested positive for a stimulant during the World Baseball Classic and has been banned from international competition for two years.

Major League Baseball will not suspend Ponson. Under the drug rules, he will be treated as a first-time offender and is subject to a medical review and fine.

The International Baseball Federation said Friday that Ponson tested positive for Phentermine, a weight-loss drug that is similar in chemical structure to an amphetamine.

“It was a prescribed medication, dietary supplement,” Royals manager Trey Hillman said Friday night in Pittsburgh, before the Royals played the Pirates. “He informed all interested parties that he was taking it and it still got flagged.”

The 32-year-old Ponson pitched well for the Netherlands last March in the WBC and later signed a minor league contract with Kansas City.

Ponson is 1-5 with a 7.27 ERA as a starter and reliever for the Royals. He has been on the 15-day disabled list since May 30 because of a strained right elbow.

Ponson was scheduled to make a rehabilitation start for Triple-A Omaha on Friday night at Memphis. He has pitched two games for Omaha, giving up two earned runs in seven innings.

“During the offseason, Sidney consulted with a physician about weight loss and was prescribed a common appetite suppressant,” said Ponson’s agent, Barry Praver. “Under the belief that this was sufficient, he did not seek further authorization, which he now understands would have been granted.

“Notably, Sidney voluntarily disclosed the use of the appetite suppressant at the time of testing. Nevertheless, Sidney accepts the penalty imposed even though he certainly was not seeking to enhance his performance nor does anyone involved in the matter believe so,” Praver said.

On Thursday, Chicago Cubs catcher Geovany Soto acknowledged that he tested positive for marijuana while playing for Puerto Rico in the WBC. An All-Star last season, he drew a two-year ban from international play but, like Ponson, was not suspended by MLB.

Ponson was born in Aruba and made his major league debut in 1998. He is 91-111 lifetime with a 5.00 ERA, and went 8-5 overall last year with Texas and the New York Yankees.

Ponson also has pitched for Baltimore, San Francisco, St. Louis and Minnesota. His best season was 2003, when he went 17-12 with a 3.75 ERA while with the Orioles and Giants.