Ever since it looked like the National Football League would lock out players at the start of the 2011 season in September, Scott Milleisen has been helping several teams prepare for the worst. Mindful that the NFL has a cap of $150 million in secured debt per club, Milleisen, new head of the sports finance group at JPMorgan Chase & Co., is working with his clients to set up term loans or credit lines so they can meet payments and cover potential losses.