Strikeforce will showcase one of its top stars when UFC veteran Nick Diaz shares the stage with women’s champion Cristiane “Cyborg” Santos and 1982 Heisman Trophy winner Herschel Walker during a Jan. 30 event at the BankAtlantic Center in Sunrise, Fla., the promotion announced on Friday. Opponents for the three have not been booked. A Brazilian jiu-jitsu black belt under Cesar Gracie, Diaz has proven himself one of the most versatile competitors in the sport. The rugged 26-year-old Californian will carry ...