Zambrano pitched last season with Miami and went 7-10 with a 4.49 ERA and was demoted to the bullpen. Of his 35 appearances, 20 were as a reliever with the Marlins. Zambrano was a free agent at the end of the season, but was unable to get a deal with a major league team.
Over the past week, there reports that Zambrano was set to sign with the Long Island Ducks of the Atlantic League, but he held off on signing that deal and continued to search for a major league contract. His deal with the Phillies is a minor league deal that carries no guarantees of being added to the major league roster, but does give Zambrano the option to opt-out of his contract if the Phillies don't place him on the major league roster by July 1.
While Zambrano has a career ERA of 3.66 in the majors, his line the past two seasons is 16-17 with a 4.66 ERA and he has made 44 starts and 15 relief appearances with the Cubs and Marlins. Zambrano pitched in all or part of 11 seasons with the Cubs before being dealt to Miami in January, 2012 for pitcher Chris Volstadt.
There is no timeline for when Zambrano will be moved to a minor league assignment to pitch in a game.