Here you go – he’s in the Knowhere Escape Mission set.
Description after the jump, lest it be considered a plot spoiler…
Team up with Groot and Rocket Raccoon to plot an escape from Knowhere! They’ve discovered the rare orb in the mining fields, only to be ambushed by the bad guys. Evade shots from the huge bazooka assembled by the Sakaaran and the evil Nebula and return fire with Rocket Raccoon’s custom space blaster. Leap into action with the gigantic posable Groot to confront the sword-wielding Nebula. Launch a fierce counter-attack so Rocket Raccoon can get away in the mining pod with the precious orb in its grabbing claw! Includes 3 minifigures with assorted weapons: Rocket Raccoon, Nebula and the Sakaaran, plus Groot figure.
source: ComicBookMovie, which also has two other sets, one of which was previously revealed.