The flamboyant 30-year-old from Paris is coming off a third-round exit at Montreal after defeating Japan's ninth-ranked Kei Nishikori in the second round last week.

A week earlier, Monfils was ousted in the first round defending his most recent of six career ATP titles at Washington, falling to Indian qualifier Yuki Bhambri.

Replacing Monfils in the Cincinnati draw will be Indian lucky loser Ramkumar Ramanathan, who meets US qualifier Chris Eubanks in the opening round.