 Complete the following phrase:  To placate the Yankees concerns about his durability, Rivera followed a strength and conditioning program in the offseason, instead of throwing. Torre said that he would try to reduce Riveras workload during the 2003 season to minimize the injury risk to his closer. However, Rivera suffered a groin injury before the season began, causing him to miss the first month. After returning on April 30, he pitched well in the seasons first half, saving 16 games in 17 opportunities. His save on June 13 against the St. Louis Cardinals secured the 300th career win for starter Roger Clemens. Rivera slumped early in the second half; over one stretch, he blew five of eleven save opportunities, but he rebounded to convert his final 15 of the season. He finished the 2003 regular season with a new career best in ERA 1.66, along with 40 saves in 46 opportunities. In the 