http://411mania.com/music/anthrax-guitarist-says-metallica-nearly-fired-lars-ulrich-in-1986/
According to Scott Ian, Metallica was very nearly as a Lars Ulrich-less band back in 1986. The Anthrax guitarist was speaking with Blabbermouth and said that the group was ready to fire their drummer, but that when Cliff Burton died in their famous bus accident the band decided to keep Ulrich on.
Ian related, “The story was that they had made a plan that they were gonna make a change and get a new drummer. We were all kind of blown away by that, because it was the four of them. It was just, like, ‘Wow! Really?’ And they were, like, ‘Yeah. When we finish this tour, we’re gonna find a new drummer.'”
He continued on, saying, “Obviously, history turned out differently for Metallica and they went on to become, arguably, one of the biggest bands on the planet. So I’m just glad it all… obviously it all worked out for my friends.”