The Miami New Times, a popular alternative weekly, said in a story Tuesday that it had obtained files through an employee at a recently closed clinic in south Florida that show Rodriguez purchased HGH and other substances.
"We are always extremely disappointed to learn of potential links between players and the use of performance-enhancing substances. ... Through our Department of Investigations, we have been actively involved in the issues in South Florida," MLB's statement said.
Rodriguez, the New York Yankees slugger currently recovering from hip surgery, has admitted using steroids from 2001-03 but insisted he stopped after that.
"We fully support the Commissioner's Joint Drug Prevention and Treatment Program. This matter is now in the hands of the Commissioner's Office," the Yankees said in a statement. "We will have no further comment until that investigation has concluded."
Other players named by the New Times as appearing in the records at Biogenesis include Melky Cabrera, Gio Gonzalez, Bartolo Colon and Nelson Cruz. Cabrera, the All-Star game MVP for the San Francisco Giants last season, was suspended 50 games in August for failing a drug test. The outfielder has signed with the Toronto Blue Jays as a free agent.
Colon, a pitcher for the Oakland A's, was also suspended 50 games in August.
The Rangers said in a statement that after being contacted by the New Times late last week, they notified Major League Baseball. The club said it had no further comment.
Gonzalez posted on his Twitter feed: "I've never used performance enhancing drugs of any kind and I never will, I've never met or spoken with tony Bosch or used any substance."
The report said that the notes of clinic chief Anthony Bosch list the players' names and the substances they received, including human growth hormone and steroids. Several unidentified employees and clients confirmed to the publication that the clinic distributed the substances, the paper said. The employees said that Bosch bragged of supplying drugs to professional athletes but they never saw the sports stars in the office.
Any player found by MLB to use banned, performance-enhancing substances, is subject to suspension.
Copyright 2013 The Associated Press.