John Isner, who beat Kevin Anderson in the third round at Indian Wells, said that he is feeling better overall despite losing two singles matches against Great Britain in Davis Cup.
''Davis Cup is a completely different animal," world No. 20 said. "I have done a pretty good job putting that behind me, but it's still extremely disappointing. I'm out here playing for myself now. I'm not necessarily wearing the stars and stripes on my shirt playing against another country right now. These wins are great, but the Davis Cup still stings a lot."
The American lost in the third round of the Australian Open, fell to Sam Querrey in the quarterfinal of Memphis, and lost in the first round of Delray Beach to Marinko Matosevic. However, Isner said that despite a slow start, he felt fine entering the season.
"I probably worked harder this off-season than I have in any other off-season,” the 29-year-old said. "Just one of those things that you can work as hard as you can but it doesn't mean anything, doesn't guarantee you success. I have had slow starts in prior years, too. I have been able to sort of overcome them and have a good year.
"But at the same time really I haven't played too many tournaments. This is just my fourth ATP tournament [this year]. There is a lot of tournaments ahead. These are the tournaments I need to play well at."
Isner will play Novak Djokovic in the fourth round. Djokovic defeated Isner in three sets in the semifinals of Indian Wells last year, while Isner upset Djokovic in the 2012 Indian Wells semifinals. "I can't ask for better conditions to go up against someone like that. These conditions suit me very well," Isner said.
"That being said, every condition suits him well. He does everything the best. That's why he's No. 1 in the world. There is no surface he's a slouch on. But I think a court like this and maybe hopefully the crowd on my side can certainly help me a lot. I seem to run into him in Masters Series events, and I would like to play him again."