On Saturday, State Farm Stadium opened its doors to welcome Cardinals fans for the “Red and White” training camp scrimmage. Star defensive end J.J. Watt was thrilled about the fan turnout for today’s event. “Cards fans, just leaving the Red/White scrimmage today. Just wanted to give a quick thank you,” Watt said in a video message on Twitter. “You guys were unbelievable. The fans, the crowd, the cheers, the support, the jerseys, the signs — just wanted to let you know we appreciate you. We appreciate you showing up. We appreciate you getting loud. And we appreciate you supporting us.…