Chris Pratt Peter Quill / Star-Lord Zoe Saldaña Gamora Dave Bautista Drax the Destroyer Karen Gillan Nebula Pom Klementieff Mantis Vin Diesel Groot (voice) Bradley Cooper Rocket (voice) Sean Gunn Kraglin / Young Rocket (voice) Chukwudi Iwuji The High Evolutionary Will Poulter Adam Warlock Maria Bakalova Cosmo (voice) Elizabeth Debicki Ayesha Sylvester Stallone Stakar Ogord Austin Freeman On-Set Groot / Phlektik Guard Stephen Blackehart Steemie Blueliver Terence Rosemore Xlomo Smeth Sarah Alami Ssssaralami Nico Santos Recorder Theel Miriam Shor Recorder Vim Linda Cardellini Lylla Asim Chaudhry Teefs Mikaela Hoover Floor Judy Greer War Pig (voice) Tara Strong Mainframe (voice) Michael Rosenbaum Martinex Elan Gale Beardy Ravager Molly C. Quinn Molly Ravager Gerardo Davila Fitz-Gibbonok Dee Bradley Baker Blurp (voice) Jennifer Holland Administrator Kwol Nathan Fillion Master Karja Benjamin Byron Davis Bletelsnort Daniela Melchior Ura Michael Rooker Yondu Udonta Pete Davidson Phlektik (uncredited)