The pair of young, struggling talents will play together for the first time in New York.
"It's important you're out on the court with the right intensity and you're sending a good message, and I've done so," says world No. 1.
After what may well have been his final US Open match, Haas calls Federer GOAT, Sampras best server and Agassi best ball striker.
Garbine Muguruza has dropped longtime coach Alejo Mancisidor and has been working with Conchita Martinez in New York.
World No. 3 Maria Sharapova has pulled out of the U.S. Open for the second time in the last three years due to injury.
Continuing a trend we've seen all season, 10 teenagers made the US Open's men's singles main draw, the most since 1990.
The Stanimal played good "D," and drew high praise from the 21-time major champ.