The Latvian, who had to qualify for this week's tournament in Delray Beach, has seen his ranking drop from a career-high No. 21 in February 2011 to No. 109.
“I was really getting pissed to see who's in the top 100,'' the 24-year-old Gulbis said. "There are some guys who I don't know who they are. Some guys, I'm sorry, with respect—they can't play tennis."
Gulbis, who has been said by some to have Top 10 potential, hired coach Gunther Berezniki last summer and said that he is in better shape and ready to fulfill his potential.
"This is the first year I really want to do this,'' Gulbis said. "I'm starting to enjoy tennis much more. Before I didn't like it, honestly. I had a couple of good wins and enjoyed it. Then I went on the wrong path and was doing wrong stuff for my game. Now, I want to play maybe five more years and do the best I can. My goal is to really win something big.”