By Mac Engel From Fort Worth Star-Telegram DALLAS—While the American women clean up in tennis, their male counterparts look decidedly Canadian. It has been so long since an American man has broached the pinnacle of sport, we have literally forgotten about tennis, and that’s a disaster for the state of the game here. You need one name, and we don’t have any. The last highlight by an American tennis player that you may remember is Dallas resident John Isner’s first-round 2010 Wimbledon match against Frenchman Nicolas Mahut that spanned three days and lasted for 11 hours and five minutes. “I can recall a lot about that match,” Isner told me in May. “When we got into the 20s [games] we knew something big was happening. The third day, I woke up that morning after playing eight hours without a result and I was amazed how good I felt. I still …