PHILADELPHIA — The starting quarterback quit during the fourth quarter of the season opener, the coaches walked out a few weeks later after their checks bounced, and the turf was so thin that it felt like concrete. This — the inaugural season of an indoor football league — was Nick Sirianni’s introduction to professional football, where the players made $300 if they won and $200 if they didn’t. And that’s if the checks cleared. “Calling it ‘professional’ is using that term very loosely,” said Dan Larlham, who became the quarterback for the Canton Legends when the starter said he had had enough…
