The New York Mets have placed pitcher Dillon Gee on the disabled list and are calling up pitcher Noah Syndergaard.
Syndergaard will make his MLB debut by starting Tuesday's game against the Chicago Cubs.
Alderson said Gee, who was scheduled to start Sunday, has a mild groin strain.
Syndergaard was ranked as Baseball America's No. 11 prospect heading into 2015. The 22-year-old is 3–0 with a 1.82 ERA and 34 strikeouts in 29 2/3 innings at Triple A Las Vegas this season.
The Mets (18–10) are playing the Phillies in Philadelphia on Friday.
- Molly Geary