PHOENIX -- Colorado Rockies outfielder Jorge Piedra said he inadvertently took a substance banned under Major League Baseball's Drug Prevention and Treatment Program but he will not fight the immediate 10-day suspension that was announced on Monday.

Piedra currently plays at Triple-A Colorado Springs. He is the second Major League player -- he is on the Rockies' 40-man Major League roster and was tested during Spring Training -- to be publicly identified for a positive drug test. Tampa Bay outfielder Alex Sanchez is currently serving a suspension.

Reached by phone on Monday, Piedra said that during the offseason, he had hamstring and foot injuries while training, and took some pills from an old prescription.

"I am a little bit embarrassed that I put myself, my family and the Rockies in this situation, but it is what it is," he said. "I had taken some pills that I wouldn't have taken if I thought I would fail a test. People are going to think what they want. No need for me to go crazy about what everybody else thinks at this point."

Steroids and their precursors are banned. Piedra said he didn't recall the specific banned substance for which he tested positive, but he was planning to have a detailed conversation with MLB officials on Monday.

Piedra also said he has not seen a list of banned substances, but he realizes that is not a defense. He will not file a grievance through the Major League Baseball Players Association and is prepared to begin serving immediately.

MLB has communicated to players and clubs that players should consult with their trainers or team doctors before taking any supplements or medicines that may contain banned materials. The MLB Players Association, which negotiated the policy with management during the offseason and modified it during Spring Training, discussed the issue in annual preseason meetings with players.

"I'll take my 10-day suspension and come back and do what I was doing before, hitting and running, doing my thing," Piedra said. "By far, it's not the end of the world. I'm not the first and I'm sure I won't be the last guy suspended."

Rockies club president Keli McGregor said in a statement released by the club, "It is unfortunate that a player within our system tested positive for violation of Major League Baseball's joint drug prevention and treatment program. As an organization we have, and will continue to support Major League Baseball and its drug testing policies."

Rockies general manager Dan O'Dowd and manager Clint Hurdle declined to elaborate on the situation, saying the team's statement was sufficient.

Piedra, who turns 26 on April 17, batted .297 in 36 games with the Rockies last season and thought he was in line to make the squad this spring, but he was sent down when the Rockies chose to go with Cory Sullivan as a backup outfielder. Hurdle said Sullivan being primarily a center fielder gave him an edge over Piedra, who played some center last year during his stint with the Rockies but didn't play it in the club's farm system.

The Rockies called up Piedra for one game this season. He went 1-for-1 as a pinch-hitter on Wednesday at home against San Diego, in between Dustan Mohr's calf injury and the arrival of outfielder Michael Restovich as a waiver claim from Tampa Bay. At Colorado Springs, Piedra is 3-for-10 (.300) with a double and three RBIs.