League of Denial 9 p.m., Channel 2
The subtitle of this controversial episode of “Frontline” is “The NFL’s Concussion Crisis.” The two-hour documentary looks at the NFL’s response to football-inflicted concussions, including its efforts to refute scientific evidence linking on-field crashes to early-onset dementia and brain damage. ESPN cut its ties to the film this summer after a 15-month collaboration, stirring rumors that the NFL pressured the network into it. (Pictured: NFL Commissioner Roger Goodell.)
New Girl 9 p.m., Fox
Well, shippers? You got what you wanted, Nick and Jess as a full-fledged couple. How does it feel? I’m not hating it, despite the fact that relationships between major sitcom characters can often lead to the horrors of on-again-off-again-ness. So far, so cute.
Tickle 8 p.m., Discovery Channel
We all ’shine on.
My Big Fat Revenge 9 p.m., Oxygen
You oughta know . . . that I quit carbs.
Chicago Fire 10 p.m., NBC
Man, couch, leader. Moucher.