The two-time Wimbledon champion has not had the happiest of times on the grass courts of SW19 in recent times, losing to someone ranked outside the top 100 in one of the first four rounds since being beaten in the 2011 final by Novak Djokovic.
The 14-time grand slam champion has struggled with injuries and form for most of the last two seasons and has only two modest titles to his name in 2015 – Stuttgart and Buenos Aires.
With just the U.S. Open remaining this season, his uncle and coach Toni Nadal has admitted that the 29-year-old's fortunes are unlikely to change in the near future.
"I want to think that it can be done," Toni Nadal told Spain's Cadena Cope radio broadcaster about his charge's chances at Flushing Meadows.
"Right now, I am realistic and the chances we have are probably thin, because we have not been able to play well for a long time.
"So it's difficult to think that we will do so at the U.S. Open but I think that it will happen at some point. I am confident there will be a tipping point and he will get his game back.
"He has been playing at a very good level for a long time and there is no clear reason for him to stop being good."
Toni Nadal admitted that the 7-5 3-6 6-4 6-4 defeat to Brown had been "really painful" since training has been going well in recent weeks.
"The opponent scarcely gave him room to get into a rhythm… but at key moments he made too many errors which were not difficult shots," he added.
"Of course, if you lose a point here and a point there the match becomes more complicated. Above all, if you don't have the confidence in your head your shots lose security and direction.
"In the end, it's a bit of everything and what we have to do is recover as soon as possible."
The American hard court season starts in August at the ATP Masters 1000 event in Montreal, Canada.
Catch all the Wimbledon action LIVE on FOX Sports Play