Las Vegas Raiders coach Jon Gruden said several of his players made a mistake when they didn’t wear masks or practice social distancing during a charity event that violated league and local COVID-19 rules. Players were seen on video without masks during the indoor event while talking and mingling with guests, who also weren’t wearing masks. “We’ve done a good job, done an excellent job,” Gruden said Wednesday. The Raiders opened the 21-day practice window for QB Marcus Mariota, who was placed on IR with a pectoral injury. QB DeShone Kizer was released from the practice squad and WR De’Mornay Pierson-El was signed to the practice squad.