NEW YORK — Fabio Fognini, the newly minted husband of Flavia Pennetta (who happens to be the 2015 US Open champion), has been causing scenes in New York—and he's only played one match.

The US Open is a memorable place for Fabio and Flavia, even if it hasn’t been Fognini’s best tournament; his record there is just 9–11. Last year, they brought Federico to Flushing Meadows ...