Frontline : League of Denial (9pm, UNC-TV) - “Frontline” examines the NFL’s concussion crisis in this documentary about the league’s response to football-inflicted concussions, including its attempts to refute scientific evidence linking on-field concussions to early-onset dementia and brain damage. The report details the case of former Pittsburgh Steeler center Mike Webster (1952-2002) whose chronic traumatic encephalopathy was likely caused by football; and also looks at the health risks of high school and college football. The documentary is based on the book “League of Denial” by Mark Fainaru-Wada and Steve Fainaru.

Supernatural (9pm, CW) - Sam collapses as Season 9 begins and Dean sends out an emergency plea via prayer to every angel in the area to help Sam. In exchange, Dean agrees to owe that angel a favor. But the request is answered by numerous angels to want to kill him. Oops.

New Girl (9pm, Fox) - Schmidt tries to break up Nick and Jess, and Winston takes his cat out for a night of debauchery before it has to be neutered.

Chicago Fire (10pm, NBC) - Severide seeks proof to confirm his suspicions about the arsonist’s identity. Meanwhile, Casey gets used to his new lifestyle and Molly’s bar is in trouble.

Person of Interest (10pm, CBS) - Reese recruits Zoe Morgan, Carter and Shaw to help him keep tabs on a chameleon playboy whose number has come up.

What’s missing here? Why, that’d be “ Lucky 7,” which debuted two weeks ago in ABC’s 10 p.m. timeslot. That unlucky show has already been canceled, and repeats of “ Scandal“ are taking its place.