CHICAGO -- Cubs owner Tom Ricketts says franchise career home run leader Sammy Sosa needs to "put everything on the table" in regard to PED use during his playing days if he is to ever be welcomed back by the team.

"Players from that era owe us a little bit of honesty," Ricketts said Saturday during the team's annual fan convention. "The only way to turn that page is to put everything on the table."

The Cubs invited a couple dozen former players to the fan convention, but Sosa wasn't one of them.

Sosa played 13 years for the Cubs, hitting 545 home runs, including three years of 60 or more. He never officially tested positive for steroids.

He hasn't been invited back with the team in any official capacity since he retired after the 2007 season. Ricketts has been ambiguous in the past about what Sosa needs to do to be welcomed back, but on Saturday, he finally explained his feelings on the topic.

"I think we have to be sympathetic to that era ... but the players owe us some honesty too," Ricketts said in response to a fan's question during a panel discussion with ownership.

After the panel, Ricketts reiterated that message but refused to expand on his answer regarding Sosa.

"I just think we need to put everything on the table and move forward, full stop," Ricketts said.

Some might find some hypocrisy in Sosa's situation considering the team employed known PED user Manny Ramirez as a hitting consultant in recent years. But Ricketts intimated it's not steroid use that bothers him as much as the denials.