Jonathan Banks was in Breaking Bad because Bob Odenkirk was busy on day of filming

In the world of TV and film, things don't always exactly go to plan for the people putting the project together.

Actors can be unavailable some days, which means filming days may have to be switched up, and it may even get to the point where that actor you had in mind for the role is not able to do it.

That was very much the case with the Breaking Bad, as Jonathan Banks would never have played Mike Ehrmantraut if things had originally worked out as planned by the show's writers.

Actually, the show's makers hadn't even planned on introducing Mike Ehrmantraut for season two, which would have certainly made it a very different show indeed.

For those die-hard Breaking Bad fans, you'll know that season two also introduced Saul Goodman, who was played by Bob Odenkirk.

And while Odenkirk was available to film for most of season two, he wasn't free for every date because of a previous commitment.

As a result, Mike Ehrmantraut was born, and nobody looked back.

AMC

But how exactly can this be the case? Well, Rhea Seehorn, who worked with Banks on the spinoff series Better Call Saul, told all in an interview on The Rich Eisen Show.

Seehorn said that writers had planned for Saul Goodman to help Jesse (played by Aaron Paul) clean up the apartment and prepare his story for when the police come knocking.

Spoiler for season two here... but Jesse's girlfriend Jane (played by Krysten Ritter) died from an overdose.

But when this scene was filmed, Odenkirk was busy, so writers improvised by bringing in a fixer worker on behalf of Saul.

It really was a stroke of genius from the writers, as Mike became a fan favorite almost instantly, meaning the writers had to keep him in for good.

In the interview, Seehorn explained: "Bob was not available for Saul Goodman to clean up her body, and so the Mike Ehrmantraut character was created.

Erik Pendzich / Alamy Stock Photo

"[Bob] was shooting something, and they wrote, when Krysten's character dies, that he comes and cleans up the body in this very cold, unfeeling manner.

"And that was going to be where his character started to go, and he was simply not available, so they made up the Mike Ehrmantraut character."

Reflecting on how Breaking Bad could have been so different, Seehorn added: "Thank goodness! Jonathan Banks played it, and now it's like, you know, invaluable to the show, that character.

"And also, I'm so glad that that's not how we saw Saul. That would've forever changed how we saw him as well."