AceShowbiz - Woody Harrelson is genuinely afraid he will accidentally let slip "Solo: A Star Wars Story" spoilers. The actor portrays the mentor-like character of Tobias Beckett in the upcoming "Star Wars" anthology film, which follows the adventures of a young Han Solo, as played by Alden Ehrenreich.

Plot details are being kept under wraps by Lucasfilm and Walt Disney studio bosses, and as Woody is one of the only people aware of the full narrative, he is very anxious not to give any of the storylines away.

"They know that I'm a little loose sometimes. You know, fast and loose. It's done well for me over the years but in this particular context, they send these guys with me," he said during an appearance on "Jimmy Kimmel Live!" on Tuesday night, May 8, gesturing to two people dressed as Stormtroopers who were standing on the stage. "I have to worry a little bit [about giving away spoilers]. I did sign [a contract], but I just kind of scribbled it. In a court of law, you could argue, 'That's not my signature.' "

Woody went on to explain that the original "Star Wars" movies made a "big impression" on him when he first watched them in the 1970s.

During the interview, the star also spoke about his most recent trip to visit his music icon pal Willie Nelson in Hawaii.

The pair will often play cards with friends, and Woody shared that sometimes the stakes get so high that he needs to do films like Solo to cover his debt.

"(The stakes) could start out as low. Sometimes as things work into the evening, Willie opens up the parameters a little more and then you're in more hot water when you get home. I've built a wing on Willie's house. He gives me credit," the 56-year-old laughed.