Pittsburgh Pirates right-hander Chris Archer underwent surgery Tuesday to address thoracic outlet syndrome and will not pitch again until 2021.

The Pirates announced Wednesday that Archer had the operation after "consulting with several leading vascular and orthopedic surgeons in recent weeks."

The surgery was performed in St. Louis by Dr. Robert Thompson. The Pirates said Archer is "projected to return to full competition for the 2021 season."

The Pirates scratched Archer from a scheduled spring training start in February because of neck tightness. He returned March 6 and threw two scoreless innings in a spring game against the Toronto Blue Jays.

Archer, 31, was a two-time All-Star with the Tampa Bay Rays but struggled last year in his first full season with the Pirates, going 3-9 with a 5.19 ERA in 23 starts.