Juan Ignacio Chela is the 8th player to retire this year following Fernando Gonzalez, Ivan Ljubicic, Andy Roddick, Kim Clijsters, Rainer Schuettler, Juan Carlos Ferrero and Gisela Dulko.
Question marks remain over Robin Soderling, Mardy Fish and possibly Gael Monfils.
Has this year been a record for player retirements?
"I have to apologise because I clearly pushed Roger so hard on Thursday!" (Andy Murray on why Federer couldn't play the WTF final).