ARLINGTON — Jerry Jones is an eternal optimist. The Cowboys owner doesn’t go long without mentioning the ‘S’ word.Super Bowl.But Jones hasn’t made a lot of predictions or guarantees this year.In fact, during the team’s annual Kickoff Luncheon to benefit Happy Hill Farm, Jones’ seven-minute speech seemed to temper the Cowboys’ prospects for 2014.“You know we have an uphill battle this year, and we do have an uphill battle,” Jones said, speaking to the players sitting around him. “But most of you had an uphill battle when you came to camp. Most of you did. And some of you have absolutely rose to the occasion. Some of you are taking the challenge on.“…This bunch and everybody in this organization knows that we’ve got our backs against the wall. Individuals on this team individually have their backs against the wall.”Jones, though, ended his speech by saying, “Let’s have a big season.” He did not make himself available to the media afterward.The Cowboys expect to have six different starters from the 2013 season opener, four of those on a defense that ranked as the third-worst in NFL history last season.