"Marrow Deep" is also notably the group's first full-length to feature new guitarist Nick Johnston alongside significant contributions from keyboardist João Nogueira. I constantly am just writing, writing, writing. We just lost Michele, and now we've lost Brent... Brent had just left the band, and it was just, like, all these crazy things going on." Asked if any of Hinds's musical ideas that were written prior to his exit from MASTODON made it on to "Marrow Deep", Brann said: "Unfortunately not. MASTODON will celebrate the "Marrow Deep" release with the upcoming "The Poisonous Weapons Tour", a nationwide run of dates with support from DEAFHEAVEN and ALCEST.