Popsugar Entertainment Nostalgia Friends Guest Stars 24 Friends Guest Stars You Might Have Forgotten About 23 September 2019 by Hedy Phillips View On One Page Photo 7 of 22 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 7 Dermot Mulroney as Gavin Mitchell Dermot Mulroney guest stars as Rachel's boss Gavin Mitchell in season nine and low-key throws a wrench in the Ross-and-Rachel love story. Previous Next Start Slideshow NostalgiaFriendsTV