The San Diego Padres reportedly have agreed to a four-year, $20 million contract with righty Nick Martinez ahead of the league’s work stoppage. The deal includes opt-outs after both his first and second years. Because Martinez and the Padres did not get the deal done before the beginning of the lockout, Martinez will technically remain a free agent until the new collective bargaining agreement is put in place. Martinez, 31, is going to return to Major League Baseball after playing with Japan’s Nippon Ham Fighters and Fukuoka SoftBank Hawks for four seasons. During his time with the Nippon Prof…