Ruben (ATP-260) starts 2020 at the Challenger tournament of Ann Arbor (United States, CH 80). He will be seeded fifth.
As the fifth seed Ruben has a bye in the first round. In the second round he will face Aleksandar Kovacevic (ATP-562) or Nick Chappell (ATP-470).
Ruben (ATP D-193) also plays doubles together with Nino Serdarusic (ATP D-510), they meet fourth seed heads Treat Huey (ATP D-167) and Nathaniel Lammons (ATP D-94) in their first round match.