Has Nadal found another secret weapon in title bid?

Aug 31, 2016; New York, NY, USA; Rafael Nadal of Spain after beating Andreas Seppi of Italy on day three of the 2016 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Robert Deutsch-USA TODAY Sports

NEW YORK (Reuters) - In 2010, Rafa Nadal tweaked his service action to give him more power and it helped him to U.S. Open glory later that year.

Six years on and despite the effects of a wrist injury, it looks as though he may have found another secret weapon as he bids to win a third U.S. Open crown.