Rocket

Assuming that Tony is indeed on the Benatar, the Guardians’ ship, Rocket has the most reason to go looking for it, and the most reason for knowing where it is. After losing Groot again, he’ll undoubtedly be eager to leave Earth and find out if anymore of his “family” survived, and being someone so obsessed with tech, you’d imagine he has some way of tracking the ships location.

Tony being rescued by a talking racoon could lead to some hilarious “Am I hallucinating?” scenes, while seeing Rocket realise he’s the only remaining Guardian would pack a punch.