O.J. Simpson has been grousing to pals that he’s “bored out of his mind” at Lovelock Correctional Center in Nevada, where he’s serving 33 years for armed robbery. So to pass the time, The Juice has returned to the playing field — although not the gridiron. “He’s playing baseball,” says our source. “As a kid, O.J. loved baseball even more than football. Now he’s got plenty of time to perfect his game.”