At Wimbledon in 2017, Medvedev was fined after emptying his wallet and throwing coins at umpire Mariana Alves following a five-set loss to Belgium's Ruben Bemelmans. He disputed a series of controversial calls and said after the match "it was very hot out there" and couldn't remember if he'd asked for Alves' removal.

Controversy arose early in the US Open, as Daniil Medvedev's first-round loss against Benjamin Bonzi featured a moment that raised eyebrows at Louis Armstrong Stadium.