The Tigers opened up the international signing period Tuesday by spending nearly half of their allotted $2.9 million to add four international free agents. Among those prospects was Dominican Republic shortstop Hector Martinez, the cousin of former major league All-Star Vladimir Guerrero. The 16-year-old Martinez, who was named to the Dominican Prospect League All-Star Game this past year, signed for $400,000. The Tigers also agreed to terms with three Venezuelan free agents, including Elys Escobar, a 6-foot-2 catcher, who signed for $300,000, according to Baseball America.