Swiss Davis Cup captain Severin Luthi tells ESPN.com that one of the reasons why U.S. Open semifinalist Stanislas Wawrinka has been able to challenge the top players more consistently is because he has become more forward-looking.

“[Stan had] a few tough losses at the beginning of the year, but we always said, ‘Look, the most important is what you do with that situation,’” Luthi said. “If you react negative and you go into a mental hole, you won’t progress. You have to accept the positive and negative out of it and try to improve; that’s all you can do. And he was very disciplined in that direction.”