World number eight Mardy Fish has admitted that it took some time for him to adapt to the court at O2 in London this evening.
The American, who has been suffering with a groin injury, lost his opening match at the ATP World Tour Finals to Rafael Nadal.
Speaking after the match, Fish confessed that he wasn't happy with his performance.
"I didn't play well," said the 29-year-old. "Obviously I got a little more comfortable after playing a set. Sort of getting used to all the surroundings with people in there.
"With the lights back, dark, it makes for good tennis. Conditions are absolutely perfect.
"That took a little bit of getting used to, I guess, 20 minutes or so."
Fish will face Jo-Wilfried Tsonga in his second Group A match on Tuesday.
