Rob Manfred says it's possible that David Ortiz was free of performance-enhancing drugs in 2003, as the slugger as long insisted.
Ortiz's name was leaked in a New York Times report that marked him as one of 100 players who failed an anonymous drug test in 2003.
Manfred said the anonymous survey testing agreed upon by Major League Baseball and the players' union returned at least 10 scientifically questionable results in addition to the 5 percent of positive tests required to trigger mandatory testing the following year.
According to Manfred, those particular tests were inconclusive because "it was hard to distinguish between certain substances that were legal, available over the counter, and not banned under our program."
"The list was supposed to be confidential. I take very seriously the commitment on confidentiality," Manfred said. "It is really unfortunate that anybody's name was ever released publicly, Point 1. Point 2: I don't think people understand very well what that list was.
"There were legitimate scientific questions about whether or not those were truly positives. If, in fact, there were test results like that today on a player and we tried to discipline them, there'd be a grievance over it. It would be vetted, tried, resolved. We didn't do that. Those issues and ambiguities were never resolved because we knew they didn't matter.
"We knew we had enough positives that everyone agreed on that we knew were going to trigger the testing the following year. Even if Rob Manfred's name was on that list, he might have been one of those 10 of 15 where there was probably or at least a very legitimate explanation that did not involve the use of a banned substance."