The Big Bang Theory enjoyed a great run for 12 seasons. However, the show could've looked drastically different. Kaley Cuoco's Penny character wasn't part of the script initially and instead, an 'angrier' character of Katie was almost cast instead.

The same would also take place with Kunal Nayyar, who was almost forced into leaving the series after the pilot, given that the network wasn't thrilled about his performance, Thankfully, Chuck Lorre had faith in the actor and as they say, the rest is history.

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Kevin Sussman continues to enjoy success, however, like some of his other castmates, the actor's involvement on The Big Bang Theory could have been drastically different.

We'll take a look back on how it all went down, and which characters Sussman was pitched before landing on Stuart.

Kevin Sussman Going Off The Script Extended His Role On The Big Bang Theory

To be clear, the cast of The Big Bang Theory rarely went off script, showing off rare this moment really was. It was an innocent scene between Penny and Stuart, in which Sussman added a soft, "I love you," when Penny walked away.

That hilarious moment was enough to get Sussman on the show regularly, while changing his character as well, to a more depressive tone.

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For Kevin Sussman, the role was a perfect fit, given that he actually worked at a comic book store. Ultimately, it was Sussman's longest stint on a TV show, and he credited the cast and their compatibility for its extended run.

He said, "I really think one of the reasons why the show is so successful is pure luck. There are really no jerks involved. Everyone is super-nice, there is not a lot of ego and stuff."

"The cast, they all are good friends. I think it is the only show, that I have been involved with, that has been so successful," the actor tells Business Standard.

Despite his success on the sitcom, things could have looked very different for Sussman and the series.

Kevin Sussman Had The Role Of Howard Wolowitz For A Few Hours

During interviews promoting the book, The Big Bang Theory: The Definitive, Inside Story of the Epic Hit Series, the cast itself learned new information they didn't know about prior.

Among the most surprising revelations included the fact that Kevin Sussman was first considered for the role of Howard. Of course, that role went to Simon Helberg, but even the actor himself was surprised by the news.

"He didn't find this out until we were doing interviews for the book, which was a shock to him," Radloff told UPI in a recent Zoom interview. "Most of the cast did not know this, so that was an eye opening thing to find out."

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According to the behind the scenes story, Sussman had the role for a few hours, but plans were ultimately nixed once it was revealed that the actor was no longer available for the role.

"Due to unforeseen circumstances which are detailed in the book, Kevin wasn't able to continue with that role," Radloff said. "He basically only had it for a few hours. "

It wasn't the only role Sussman was up for, according to the actor, he ended up turning down another role on the series before landing on Stuart.

Kevin Sussman Was Also Offered The Role Of Kripke But Turned It Down

Kevin Sussman landed on Stuart, which was initially a role that was supposed to last one episode. Prior to Stuart Bloom, Sussman had another offer to play Kripke. However, given his commitments to a film at the time, he was forced into turning down the role of Sheldon's rival.

The actor stated alongside Roster Con, “Actually Chuck Lorre, the creator of TBBT, originally wanted me to play the role of Kripke […] but I couldn’t do it because I was doing a movie at the time. So I ended up doing Stuart which was just supposed to be like a day on the show […] and then they had me come back a couple of times and then the rest is history.”

We can all agree, the actor ended up taking on the perfect role and one he thrived in for several seasons.