The Big Bang Theory Guest Star Who Almost Played Leonard Before Johnny Galecki

Playing Leonard Hofstadter on “The Big Bang Theory” was undeniably a career-defining moment for Johnny Galecki. Perhaps the least obliviously nerdy of the series’ endearingly awkward core group of scientists, Leonard offered some sense of grounding to his socially oblivious friends’ escapades.

While it’s hard to imagine anyone else bringing Leonard Hofstadter to life now, Galecki was far from the only star in consideration for the role. In fact, the actor wasn’t even initially approached for the role of Leonard. Originally, the creators of “The Big Bang Theory” had Galecki in mind for Sheldon, but the opportunity to explore a…