Chicago police say they are investigating an accusation that Chicago Cubs All-Star shortstop Starlin Castro sexually assaulted a woman last fall, but no charges have been filed at this time and Castro's representatives deny the allegation.

"The Cubs are aware of a police report involving Starlin Castro," Cubs general manager Jed Hoyer said. "An allegation like this is something we take very seriously.

"We don't have enough information to make any other comment or answer other questions at this time. We are hopeful when the facts are brought to light that Starlin will be cleared of any wrongdoing."

WBBM Newsradio in Chicago reports that the unidentified woman, who is in her 20s, was at a River North nightclub Sept. 29 when she met Castro. After 3 a.m. CT, she went with a friend to his apartment, where she alleges that the assault took place.

The woman went to a hospital the next evening and police became involved, while Castro left for his offseason in the Dominican Republic, according to the report.

The police are now hoping to talk to Castro, a source told ESPNChicago.com. Castro has been scheduled to return to Chicago next week for the Cubs Convention.

"We expect our players to behave with the highest level of respect on the field, off the field and in the community," Hoyer added. "Being a member of the Cubs carries along with it a very high standard of conduct and responsibility. While we cannot address this particular matter at this time, we want to emphasize that this organization is committed to being respectful members in the community and being positive examples for our great fans."

Jay K. Reisinger and Michael P. Gillespie, attorneys for Castro, issued a strongly worded statement.

"We are aware of certain allegations that have been made against our client, Starlin Castro," the statement says. "We have thoroughly investigated this matter, and we are confident that these allegations are baseless. Given the sensitive nature of this matter, we cannot comment any further."

Castro has been tabbed as the new face of the Cubs franchise under Theo Epstein, the club's new president of baseball operations.

Castro is scheduled to attend the annual Cubs convention fan event next weekend at a downtown hotel, and Hoyer said he still expects Castro to be there.

Castro is scheduled to participate in a segment with fans where he and a couple other players are to discuss their experiences in the Dominican Republic and Mesa, Ariz., where the Cubs hold spring training.

Hoyer wouldn't say whether the Cubs expect Castro to be at spring training.

"There is a time and place to comment on this and it's not right now," he said.

In his second year in the big leagues, Castro made his first All-Star team last season, batting .307 with 10 home runs, 66 RBIs and a league-leading 207 hits.

Information from The Associated Press was used in this report.