MODERN FAMILY - "Message Received" - Jay, Gloria and Manny (above) challenge each other to step outside their comfort zone and try something new. (Peter "Hopper" Stone/ABC)

As if the physical demands weren’t enough, the castaways now have to worry about their mental health on “Survivor” (CBS at 8 p.m.) after one finalist is stricken with paranoia.

The Top 4 vocalists, made up of Jena Irene, Caleb Johnson, Jessica Meuse and Alex Preston, perform with the theme “Love: Breakups and Make-Ups” on a live, two-hour “American Idol” (Fox at 8).

After teasing one another relentlessly about their phobias, Manny, Jay and Gloria decide to try something new, with varying results, on “Modern Family” (ABC at 9).

In part one of a two-part episode of “Criminal Minds” (CBS at 9), prostitutes are being murdered in Texas, and evidence suggests a religious cult could be to blame.

RETURNING SHOW: The “Hollywood Exes” (VH1 at 9) Season 3 opener welcomes new cast member Shanna Moakler — who was married to Blink-182 drummer Travis Barker from 2004 to 2008 — and settles the drama between Mayte and Jessica.

After Rayna learns that Luke has been injured in Afghanistan, she arranges a charity concert at Fort Campbell (Ky.) on “Nashville” (ABC at 10).

FINALE WATCH: In an effort to make things right with one another, the “Flipping Out” (Bravo at 10) design team goes on a New Mexico retreat where they participate in various team-building exercises in the Season 7 closer.

RETURNING SHOW: The third season of “Catfish: The TV Show” (MTV at 10) opens with an aggressive Catfisher named Zoe who starts demanding passwords and hacking accounts to track down to whom she’s really been talking.

FINALE WATCH: In the show’s Season 14 finale, the crime investigated by the “CSI: Crime Scene Investigation” (CBS at 10) crew goes way back, 25 years to be exact, to an infamous mob heist.

Cmdr. Perry notifies the unit that Pulpo has been released to help with their case on “Chicago PD” (NBC at 10) and a difficult part of Lindsay’s past resurfaces.

Actor Zac Efron and celebrity restaurateur Guy Fieri are on “The Tonight Show Starring Jimmy Fallon” (NBC at 11:35), along with a musical performance from Sarah McLachlan.

Songstress Mariah Carey and Rick Harrison of “Pawn Stars” come to the “Late Show With David Letterman” (CBS at 11:35 p.m.), with music from the Whigs.

“Jimmy Kimmel Live” (ABC at 11:35) hosts an interview and concert performance from Pharrell Williams.

Rachel Lubitz