Bernard Tomic claimed that he has "slacked off" recently after being defeated in the first round of Wimbledon in four sets by wildcard David Goffin.
The Australian 20th seed took the first set, but lost the next three and has admitted that since his surprise quarter-final appearance last year he has not worked hard enough.
"To have talent is one thing, it's huge for any sport," Tomic said.
"[However] I have sort of slacked off a little bit and look what it's costing me. [In the] last eight, nine weeks I'm losing a lot of first, second rounds. So it's not my quality of tennis."
Tomic is representing Australia at next month's Olympic Games.
