Sam Querrey spoke highly of U.S. teenager Jared Donaldson, who he defeated in straight sets in the second round of Memphis.

“It’s tough playing a young guy because it feels like all the pressure is on you,” said Querrey. “He hits a big ball. Big serve, big forehand, and doesn’t seem too intimidated to go for his shots. In the long run, that usually pays off. He’ll be going deep in these tournaments very soon.”

Donaldson previously beat another American teenager, 17-year-old Stefan Kozlov, in straight sets. He qualified for his first ATP tournament at the 2014 Citi Open in Washington.