Former world No. 8 Jack Sock won't be making his return to the Knoxville Challenger this year as he has decided to withdraw from the tournament. Sock, a four-time ATP champion, is going through some of the most difficult times of his career as he is set to drop out of the ATP rankings list after failing to win a match outside the Laver Cup this year.
The American needed to avoid a first round exit at this week's Charlottesville Challenger in order to keep a ranking but he failed to do so as a back injury forced him to retire his opener at the tournament to Sekou Bangoura.
Following the withdrawal of Sock, a place in the Knoxville main draw has opened for Great Britain's Ryan Peniston, who has no previous appearances at the American Challenger event. Sock, 27, failed to make it past the Knoxville qualifying in 2011, before picking up back-to-back first round exits in his lone two main draw appearances at the tournament in 2012 and 2013.