"I think, considering the era, it was a tough decision," the former Baltimore Orioles pitcher said just hours before he and several other Hall of Famers attended Tuesday's 21st Annual Baseball Assistance Team dinner at the New York Marriott Marquis Hotel.
"[Former St. Louis Cardinals pitcher] Bob Gibson, who is on the board here at B.A.T., always said, 'If I played in an era where people were taking something, and I thought it was going to make me better, you know what, maybe I would've thought about doing it.'"
After years of denying he used steroids, McGwire this month confessed to Bob Costas on MLB Network that he used performance-enhancing drugs throughout his career and during the 1998 season, when he broke Roger Maris' home-run record.
"You have choices," Palmer said. "He said he took them for health issues."
When asked if he believed McGwire's explanation, Palmer replied: "Well, you know, it doesn't really matter what I believe. But at least he owned up to it. And I don't know if he told us exactly why [he took them]. But I do think it enhances performance."
McGwire has denied steroids helped him hit the long ball.
"It's hard to hit home runs," Palmer said. "And I wish they were real because it helps the game. I remember back in 1998. They were all meaningless games except for [Sammy] Sosa and all that. But you kind of suspected something was going on. I wish him the best, but on the other hand I wish Pete Rose the best ... I'm not a guy that holds grudges. Mark McGwire is a terrific guy. [But] I don't know how honest he was."
As for whether McGwire deserves to be in the Hall of Fame, Palmer said, with a smile: "I don't vote."