WHO'S YOUR DADDY?

Yankee superstar Randy "Big Unit" Johnson has a secret 16-year-old love child he's never spoken to - but the pitching ace now wants the girl's mom to return nearly $100,000 he's paid for day care. The $16-million-a-year hurler last month petitioned a judge to recoup 8 years of day-care expenses - plus interest - after the teen's mother asked Johnson to buy a truck and computer for the girl, Heather, as well as cover community college expenses. The hot-tempered future Hall of Famer, who is a born-again Christian, has seen Heather only once - right after her out-of-wedlock birth in 1989, and he demanded a paternity test when Roszell first sought child support in 1998. The 6-foot-1 high-school student "looks like him, walking and talking, a young girl with attitude," said Roszell, who is married and has a son. The New York Post, March 28, 2006