Production of Season 8 of "The Big Bang Theory" might be put on hold, as most of the show's cast members do not have contracts.

The show was supposed to start shooting at the end of July, but many of the stars' contracts expired at the end of Season 7, Deadline noted.

Jim Parsons, Johnny Galecki, Kaley Cuoco-Sweeting, Simon Helberg and Kunal Nayyar still have no contracts. In 2010, the five faced salary negotiations, but because they were under contract, they needed to show up for work. Their agents worked on getting them pay raises while they filmed the show.

Melissa Rauch and Mayim Bialik got new contracts last fall.

The shooting of Season 8 hinges on the five main characters signing new contracts, but Deadline said negotiations aren't expected to go too long. Plus, even if shooting starts after Labor Day, an hourlong episode should still air for the Sept. 22 season premiere.

Since 2010, Parson has gotten new representation. He was at Innovative Artists before, and now he's with CAA. Galecki has moved to WME.

For Season 7, Galecki, Parsons and Cuoco-Sweeting made about $350,000 per episode.

"Given the enormous success on 'Big Bang,' a blockbuster network and off-network hit which some estimate could generate up to $3 billion for Warner Bros. TV, Galecki, Parsons and [Cuoco-Sweeting] could go into 'Friends' territory with new salaries in the neighborhood of $1 million per episode, plus a bigger piece of the backend," Deadline wrote.

On Wednesday, Breathecast suggested that Penny and Leonard's wedding might be as soon as the Season 8 premiere. But The Inquisitr believes the season will revolve around the wedding planning.

Perhaps more questions will be answered when the cast heads to San Diego Comic-Con, which runs from July 24 to July 27.