TNT commentator DOUG COLLINS agreed to a deal to coach the Pistons for $6.5M over five years (DETROIT FREE PRESS, 4/28)....Yankees Owner GEORGE STEINBRENNER faces a Senate probe over Navy ship building contracts (N.Y. DAILY NEWS, 4/28)....SANDHI ORTIZ-DEL VALLE's quest to officiate in the NBA is profiled by Lars Anderson in SI. Ortiz-Del Valle, who officiates in the USBL, is the first woman ever to work a men's pro game. Also, NBA VP/Ops ROD THORN's job as discipline czar is profiled by Jack McCallum (SI, 5/1). ATHLETES TURNED TV STARS: PATRICK EWING made a guest appearance on "Mad About You" last night (NBC, 4/27).... "Extra" reported on MIKE PIAZZA's appearance on "Baywatch." In the show, Piazza is seen swinging a baseball bat on the beach as the show's star PAMELA ANDERSON walks up and says, "Excuse me, why are you swinging that baseball bat?" Piazza: "Well, I'm a baseball player." The two then run off to save a drowning swimmer ("extra," 4/27).