Sam Querrey is no longer working with coach David Nainkin, according to reports. Nainkin is at the Tulsa Challenger with William Blumberg, reports Colette Lewis of Zootennis.com.
A change from his long-time coach seems to have affected Querrey positively. The American has won back-to-back Challenger tournaments during the previous two weeks, first in Napa Valley and then in Sacramento, returning to the Top 50 for the first time since the beginning of the season.
Querrey is said to be working with various USTA-affiliated coaches, including Stephen Amritraj.
His next ATP event is scheduled to be at Valencia in two weeks.