He sees one of the PCs who looks like his former "Master" which he served. It turns out that PC is actually a distant descendant of his former master. So, you can role-play him calling the PC by his former master's name, assume he likes the same stuff, etc. (To be clear, by master, I do not necessarily mean a master/slave relationship, more a master/servant one.)
OR
Depending on his scores and class, etc. maybe he was a lost diplomat to an ancient kingdom of a race of one of the PCs, and looks to that PC.
OR
If the PCs freed him, perhaps he feels he owes a bond to them for releasing him.
OR
Any other number of things... more info on your PC would help. Personality, what was his backstory before he was frozen, etc.
Oh, and welcome to the forums. Have a Like.