Howard Schultz is putting his presidential campaign on hold, in the latest signal that the coffee mogul’s 2020 bid is losing steam.

Schultz told supporters he will take the summer off to recover from back surgery, in an email obtained by Huffington Post.

The former Starbucks CEO’s campaign staff is also shrinking. In May, GeekWire reported on the departure of Mike Develin, a former Instagram and Facebook analytics chief who left Schultz’s team just five months after he was hired. On Wednesday, Schultz announced he was letting most of his campaign staff go, only retaining employees in senior leadership positions, according to Huffington Post.

Schultz first floated the idea of running as a centrist independent candidate in January. He discussed his vision on a multi-state tour to promote his newly-released book, From the Ground Up: A Journey to Reimagine the Promise of America. But the campaign fizzled in April when Schultz’ began experiencing back problems.

Schultz’s decision to re-enter the race reportedly hinges on whether former Vice President Joe Biden clinches the nomination.