LOS ANGELES– Fox’s hopes for a rebound by its struggling new Monday lineup were dashed this week.

In its second outing, the freshman drama “Skin” flopped, placing a distant fourth with a 2.2 rating/5 share in the key 18-49 demographic and 5.1 million total viewers, according to figures from Nielsen Media Research. That was down 19 percent compared with last week’s premiere, whose numbers were considered surprisingly low.

“Skin’s” 8 p.m. lead-in, the reality romance “The Next Joe Millionaire,” slid even further, down 22 percent in the demo to a 2.5/7.

The lackluster performance was especially surprising because the competition was somewhat weaker than last week.

The fate of “Skin” and “Joe Millionaire” is considered critical to Fox because they currently occupy one-quarter of the network’s 16-hour weekly schedule.

Fox is building exposure for “Skin” by repeating each week’s episode in the 9 p.m. Thursday slot. And two originals of “Joe Millionaire” are due to run each week throughout the November sweep.

“Skin’s” lagging performance led at least two analysts — Fulcrum Global Partners and Jessica Reif Cohen of Merrill Lynch — to warn Tuesday that Fox will likely be forced to give advertisers sizable make-goods for failing to meet overall ratings targets this season.

“We expect ‘Skin’ to be pulled within the next couple of weeks, if not earlier,” Fulcrum wrote in a research note.