He bashed a team-high 26 homers for the A's in 2007, becoming a power hitting sensation immediately after he was traded to Oakland from San Diego on May 3.
The longtime minor league journeyman headed home to Pennsylvania for the offseason having finally solidified a spot in a major league lineup.
Then the Mitchell Report hit the baseball world Dec. 13, and Cust was among the 85 players mentioned in the document in connection with using performance-enhancing drugs.
Larry Bigbie, a former teammate of Cust's in the Baltimore Orioles' farm system, claimed in the report that his locker was next to Cust's in 2003 and that Cust told him he had used steroids before and could help Bigbie obtain some of his own.
Cust addressed the topic with reporters for the first time Saturday at the A's annual FanFest at McAfee Coliseum. He flatly denied ever using performance-enhancers, said he couldn't recall such a conversation with Bigbie ever taking place, and claimed he and Bigbie weren't even friends.
"I don't remember having a conversation about that," Cust said. "He may have misinterpreted something I said, but honestly I don't remember a conversation that took place about that. I don't remember a lot of things from five years ago, but he may have misinterpreted something I said at some point.
"I read the report obviously when it came out. (Bigbie) said he had a locker next to me and stuff like that. I didn't have a locker next to him."
Asked point blank if he had ever tried steroids or human growth hormone, Cust answered with a definitive "No."
Cust's inclusion in the Mitchell Report underscores what many claim as one of the document's weaknesses: It includes written documentation linking some players to performance-enhancers, but Cust was included based solely on the testimony of one person -- Bigbie.
Cust said he was notified by Mitchell's investigators that he would be mentioned in the report and was given the chance to explain his side. Like most players, he passed.
"I knew I had nothing to hide," Cust said. "I asked the players' union what their advice was. They said, 'We're asking guys not to talk to (Mitchell's investigators) because they're going to try to get stuff on other players you played with.' And since I knew I had nothing to hide, I (said) 'All right, that's fine.' "
It remains unclear why Bigbie might give false information about Cust, and Cust isn't interested in knowing why. He said he hasn't spoken with Bigbie since that 2003 season.
Cust, listed last season at 6-foot-1 and 231 pounds, has been known for his power at the plate since he began his pro career in 1997. Before joining the A's, he saw big league time with four teams but played in just 70 games.
He knows his reputation might be tarnished in some fans' eyes, but what troubles him most is that people could disregard the work ethic that led to last season's long-awaited success.
And the fact that he was linked to steroids left him with some explaining to do this winter at the youth baseball school he owns in Flemington, New Jersey. Cust said he took the opportunity to not only defend himself to the kids, but also point out the danger of using performance-enhancing drugs.
"I think the people that have played with me, and know me, know the type of person I am," he said. "They know that I work hard. I think I work harder than anybody else."
A's general manager Billy Beane said only that he spoke with Cust after the report, and the GM seems to consider it a dead subject. Cust offered his gratitude for the organization sticking behind him.
"I think it gets blown out of proportion a little bit," A's pitcher Justin Duchscherer said. "Unless they can prove those guys did what (the Mitchell Report says) they did, I can't say that he did or didn't. And I'm not going to judge him. He hit 26 home runs last year and we had steroid testing, and he cleared his test."
Contact Joe Stiglich at firstname.lastname@example.org.