It’s probably not a good year to be on the bubble at Fox.

With the network already looking ahead to a fall boasting newcomers like “The X Factor” and “Terra Nova,” the network isn’t going to have a lot of room for its crop of so-so players.

That means shows like “Lie to Me,” “Human Target” and even “Fringe” have reason to be concerned. Speaking to reporters Tuesday at Fox’s portion of the TV Critics Assn. press tour, Fox Entertainment prexy Kevin Reilly admitted he faced several tough calls come May.

“Sometimes things have creatively drifted (and it’s easy to cancel a show),” he said. “But in all instances here, these are good teams, good stars and I like the shows. It’s a shelf space issue. Not all shows are going to make it.”

Many of those bubble shows have hit a ratings wall, Reilly noted, and pointed out that Fox does need room to cultivate new fare.

“We need a next generation of hits,” he said.

Reilly cautioned not to write off “Fringe” just yet, however. The exec said he’d be happy if at least 80% of the show’s Thursday night viewers made the move to its new Friday home.

“I’d be discouraged if the audience that has stuck with it already all of a sudden say ‘I’m out of here’ because it’s on a new night,” he said.

One other show that still awaits its fate on Fox, but for an entirely different reason: Long-running hit “House.” Reilly confirmed that the network and Universal Media Studios (which is the studio behind the show) have not yet begun negotiations on a license renewal.

Fox’s deal for “House” expires at the end of this season.

“It will be one of Mr. Greenblatt’s first jobs,” said Reilly, referring to incoming NBC Entertainment chairman Bob Greenblatt.

Fox Entertainment Group chairman Peter Rice dismissed reports that “Terra Nova” had suffered from cost overruns, noting that the show’s pricy sets and special effects have been amortized over 13 episodes, not just the pilot.

“That’s why we ordered directly to series,” he said. “It would be the most expensive first-year show we’ve had, but not the most expensive shows on our air.”

Reilly said exec producer Steven Spielberg has been extremely involved in the show’s creation.

“Steven’s had an unbelievable level of engagement,” he said. “He watches way more TV than I do and he’s really up on it.”

Meanwhile, the question of Fox’s major fall disappointment, “Lone Star,” creeped up again as the execs were asked whether the show could have been saved.

“The truth is it failed,” Rice said. “It doesn’t mean we don’t like the show.”

Reilly took issue with crix who turned “Lone Star’s” failure into an indictment on broadcast.

“I don’t believe for a second that all the great shows are just on cable,” he said. “Some commentary after the fact was not completely fair.”

As for the coming “American Idol” and “X Factor” one-two punch, the execs dismissed concerns that the airwaves would be overly saturated with performance competition series – at least on their air.

“We have the biggest and largest in ‘Idol,’” Rice said. “And ‘X Factor’ has Simon Cowell. They’ll run at different times of the years. And ‘X Factor’ is very different from ‘Idol.’”

That said, Reilly admitted that there probably wasn’t room for the sheer crush of dance and singing competitions coming to TV in the coming year.

“We’ve got the gold standard,” Reilly said. “Everyone else is trying to chase it.”