Tim Matheson Says “Animal House ”Director Made Sure John Belushi Was Clean on Set

"We expected a colossal coked-up prima donna to arrive from New York," the actor writes in his new memoir 'Damn Glad to Meet You'

In a new book, Tim Matheson is looking back on memories of his late friend John Belushi.

The actor, 76, recalled filming the 1978 comedy film National Lampoon's Animal House in his new memoir Damn Glad to Meet You: My Seven Decades in the Hollywood Trenches, which hit shelves on Tuesday, Nov. 12. The Virgin River star wrote that Belushi is "who I’m asked about more than anyone else I've ever worked with, and I've worked with almost everyone."

Matheson and Belushi starred in the box office hit as college students in the Delta Tau Chi fraternity. Now, in his book, he has revealed that director John Landis made sure his colleague was "clean" while filming the movie given his history with drug abuse.

"Belushi, for the record, was clean on set during Animal House," Matheson wrote. "If he did anything, it was away from the rest of us, and he never gave any signs he was up to anything."

The actor added that the director was keeping a close eye on Belushi. "Landis had warned Belushi to keep on his best behavior and made sure it was a drug-free set," he added.

Upon starring in Animal House, Matheson recalled that Belushi was "one of the biggest celebrities in America" whose reputation preceded him. "Rumors of wild parties after SNL aired each Saturday were already trickling out on entertainment and gossip pages," he added.

For that reason, the cast had low expectations of Belushi's arrival but were pleasantly surprised by his behavior. "We expected a colossal coked-up prima donna to arrive from New York to lead the Deltas. The exact opposite is what we got," he wrote, adding that Belushi "couldn’t have been more wonderful."

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"Everybody was in awe of the guy, and yet he proved so normal," Matheson added. "Approachable. Genuinely friendly. All the id and raw energy was for characters in a scene and montage. John – away from an audience – was quiet, thoughtful and gentle."

The Hart of Dixie alum praised Belushi for his welcoming personality on set, saying that it was a break from the decades-long conflict between "East Coast and West Coast actors."

"Belushi wasn’t buying any of that crap," he wrote. "He treated every actor, no matter where the person was from, exactly the same."

According to Matheson, Belushi was only on set three days a week due to his filming schedule on Saturday Night Live, for which he was an original cast member. The comedian worked Monday through Wednesday on the movie and flew back to New York City for the second half of the week to work on the sketch show and go to the “famed postshow party."

Matheson recalled seeing Belushi and his frequent collaborator Dan Aykroyd on tour and noted that he had "two enormous bodyguards whose primary job was to keep people from giving him drugs."

The actor later worked with Belushi and Aykroyd in Steven Spielberg’s 1979 war comedy 1941. "It was impossible to not see that the fame and lifestyle had taken their toll," he wrote of working with Belushi, at the time. "He wasn’t the same John. He looked exhausted, distracted."

Related: Dan Aykroyd Says He'll Never Forget the 'Trauma' of Having to Tell John Belushi's Wife He Had Died

Matheson felt there was "nothing" he could do to intervene, especially given Belushi’s growing celebrity status. "The notion of pulling him aside to scream, 'You’re one of the most talented actors I’ve ever met! … Don’t ruin this! Get off the drugs!' just wasn’t realistic,'" he wrote. "He was a grown man. A megastar. We were friendly but not friends enough for me to free him from this. John was in his own orbit now."

Belushi died a few years later in 1982 at age 33 from combined drug intoxication after he was injected with a narcotic cocktail consisting of heroin and cocaine.

Upon news of Belushi's death, Matheson recalled that he was "filled with sadness but not surprised."

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Damn Glad to Meet You details Matheson’s grand Hollywood career and his collaborations with industry greats such as Chris Farley, Chevy Chase, Penny Marshall, Dick Van Dyke and more.

Damn Glad to Meet You: My Seven Decades in the Hollywood Trenches by Tim Matheson is now available, wherever books are sold.