Sam Querrey has parted ways with coach David Nainkin and has hired Brad Gilbert on a trial basis, TENNIS.com has learned.

Gilbert told TENNIS.com that being an ESPN analyst will still be his main job, and that his position with Querrey will be part-time and will be on a week to week basis.

Gilbert is unsure as to how many tournaments he will work with Querrey as the relationship is still in a trial period. He will travel with his fellow Amercian to next week's tournament in Memphis.

Gilbert has coached a slew of notable players, including Andy Roddick, Andy Murray and Japan's Kei Nishikori, whom he consulted with on a part time basis. Gilbert and Nishikori decided not to renew their contract at the end of last season.

A source told TENNIS.com that Querrey and Nainkin sat down a couple of weeks ago and that Querrey made the call himself to move in another direction.

Former top 20 player Querrey has fallen to No. 85  in the rankings, partly due to undergoing elbow surgery last June. Querrey may decide with Gilbert to hire a traveling coach. He might also use a coach from USTA  Player Development. Zootennis' Colette Lewis first noted the Gilbert hiring. — Matt Cronin