By Rory Robinson The Kansas City Chiefs could be getting a boost for Super Bowl LVIII with the return of running back Jerick McKinnon from injury. He used to play for their opponents, the San Francisco 49ers, and could be a secret weapon for the Chiefs. McKinnon was put on the injured list on Christmas Eve due to a groin injury, just before a game against the Las Vegas Raiders. Clyde Edwards-Helaire stepped in for him during his absence. Because of a series of injuries, McKinnon was limited to 21 carries for 60 yards and one touchdown this season. But he also showed his skills in the passing g…