The US sprinter who battled foot injuries last year has struggled to find his form and not run under 10 seconds in the 100m and has won only one race all year.
  
"I think my performances this season sucked, to put it simple," Crawford said before of the Shanghai Golden Grand Prix.
  
"Last year I was injured, this year who knew what happened. A lot of stuff went on. I was like, basically 'F' it. I was just cruising this year.
  
"The World Championships are next year, I've just got to build.  My attitude wasn't in it, I wasn't in it, I'm just looking forward to next year."

With stablemate Justin Gaitlin recently given an eight year Crawford refused to be drawn on whether that gave him the opportunity to become the world's top sprinter.
  
"That's my friend, I'm going to be with him through thick and thin. I'll leave it up to God to see who steps up to be number one," he said.

Crawford, one of seven current Olympic champions appearing at the season-ending Golden Grand Prix, will run in the 100m in Shanghai on Saturday.