Cole Hamels' start on April 6 against the Boston Red Sox at Citizens Bank Park - which manager Ryne Sandberg made "official" on Sunday - will mark only the second opening-day start of the lefthander's career.
Hamels, 31, and entering his 10th major-league season, did not start on opening day last year because of biceps tendinitis. Cliff Lee started instead and Hamels made his 2014 season debut on April 23.
The previous April featured Hamels' first career opening-day start, at Turner Field in Atlanta. He was tagged with the loss after allowing five runs on seven hits over five innings.
In the preceding three seasons, Roy Halladay got the nod on opening day for the Phillies. Brett Myers started on opening day from 2007 to 2009.