Justin Timberlake On His 30th Birthday Plans & Mark Zuckerberg’s ‘SNL’ Cameo

Justin Timberlake turns 30 on Monday, but don’t expect a blow out bash from the singing and acting superstar.

“I’ll keep it mellow,” “The Social Network” star told Access Hollywood’s Shaun Robinson on the red carpet at The 17th Annual Screen Actors Guild Awards on Sunday.

Justin will indeed have to take it easy, as a new film he’s been working recently took a real toll on his physique.

“I have a pinched nerve in my neck and I just tore my calf recently doing this movie,” Justin said. “I feel like I’m getting all these signs from the [cosmos], like, ‘Hey, man. You’re getting old!’

“But I’m excited about my 30’s,” he continued. “I’m very excited about them.”

While Justin won’t be partying, he will be having some kind of adventure on Monday.

“I’ll be working,” he laughed.

Justin also plans to fit in some time to catch up on some TV – in particular, “Saturday Night Live,” which was hosted over the weekend by his “Social Network” co-star Jesse Eisenberg.

Justin said that so far, he has only seen Jesse’s monologue, which featured a cameo from “The Social Network’s” real-life icon – Facebook founder Mark Zuckerberg. The “SNL”-hosting vet told Shaun he liked what he’s seen thus far.

“I was in Tennessee [Saturday] night. I literally got off the plane just a couple hours ago from Tennessee. I saw the monologue and I’m going to go back and watch the rest of it online, but the monologue is real funny,” Justin said. “I can’t believe that Mark Zuckerberg came to the show. That was really cool of him.”