The rock band are so impressed with the Hollywood heartthrob's band, Dead Man's Bones, that they have sent the 32-year-old actor an open invitation to support them on tour.
Brian Fallon, Gaslight Anthem's frontman, uploaded a picture to his Instagram page of Ryan playing guitar alongside the caption: ''Hey Girl... Dead Man's Bones is actually really good. You come tour with us and not make Only God Forgives 2.''
Ryan and his musical partner Zach Shields have only released one album to date, 2009's self-titled 'Dead Man's Bones', and all their songs are eerie love stories about ghosts and monsters.
The Gaslight Anthem are currently working on their fifth record, which will be inspired by Pearl Jam, and they admitted they were looking for a ''weird'' new approach, so Ryan's input could be just what they need.
Brian recently said: ''We're searching for something new to do with songwriting, rather than just piecing together verses and choruses in more of a traditional sense.
''We're looking for some other thing - not some other genre, but something else. And it might not be the favourite of everyone, but [it] might be the 'weird' album coming up. I'm pretty sure it is.''
The band are due to jet off to Europe next week to play a number of festival dates.
David Bowie and Rag'n'Bone Man both won two awards at the 2017 BRIT Awards at the O2 Arena in London last night.
The grime superstar will top the bill on Saturday night at Finsbury Park's Wireless Festival in July, with The Weeknd and Chance The Rapper also...