It will be the second Opening Day start of Hamels' career. He will be followed by Aaron Harang in the rotation, Sandberg said.
Hamels has been available on the trade market and in February he told USA Today he wants to be traded because he knows Philadelphia will not be a contender this season.
Last season, the 31-year-old went 9-9 with a 2.46 ERA and 198 strikeouts in 204 2/3 innings. He is signed through 2018 and is scheduled to be paid $22.5 million every season until the contract ends. The contract also calls for a $20 million club option or $24 million vesting option for the 2019 season.
The Phillies' Opening Day is on April 6 at home against the Boston Red Sox.
- Molly Geary