Alexander Bradley of East Hartford was told to testify before the Fall River, Mass., grand jury that is looking into the slaying of Odin Lloyd last month.
Bradley has a civil lawsuit pending against Hernandez which alleges the football star shot him in the eye outside a Florida nightclub in February.
Investigators want to hear about the Bradley case and potential similarities between the Florida incident and shooting death of Lloyd in Massachusetts.
The Hartford (Conn.) Courant said a Connecticut judge rejected Bradley's contention that appearing in Massachusetts would present a hardship. Bradley's lawyer also backtracked on the allegation his client was shot by Hernandez.
"He's not made that kind of statement," attorney Robert Pickering told the court, adding Bradley does not know who pulled the trigger and has nothing to contribute to the grand jury's investigation.