There is still no possibility that Gendry, played by Joe Dempsie, Robert Baratheo's (Mark Addy) bastard son, will reappear in "Game of Thrones." This year's season has many characters returning as those missing in the previous seasons appear again.
Gendry has not been seen after season 3 when he escaped Dragonstone with the help of Davos Seaworth (Liam Cunningham). He avoided Red Woman, Melisandre (Carice van Houten) who wanted to burn him and use his "king's blood."
It is worth noting that the storyline of Gendry varies a bit between the TV show and what is found in the books, according to PopSugar. In the latter, the character does not encounter Melisandre. He joined the Brotherhood Without Banners after they captured him, Arya Stark (Maise Williams) and Hot Pie (Ben Hawkey).
It is not clear if he will come back but there are several existing fan theories about him. Some speculated that he is hiding in Flea Bottom until he can claim the Iron Throne since the Westerosi law says that if the father has no trueborn children, the bastard can inherit and Gendry is the last alleged Robert Baratheon's heir. If Tommen (Dead-Charles Chapman) dies, Gendry could claim for the Iron Throne though he may not interest in political leadership.
Dempsie's character may have decided to row the Trident and explore Westeros' most extensive river network. He may meet Brienne (Gwendoline Christie) and Podrick Payne (Daniel Portman) who are rowing around the region. Being good at making cool helmets, he may also be making metal tasks to make a living.
Gendry could be around Fingers, if he is reluctant to travel far from home as Fingers can be a nice compromise. He could take the role of an Aegon in Volantis, just like Young Griff in the books. He could collect an army to wage a war in Westeros to claim his birthright.
Furthermore, Gendry may not be a bastard. There were theories that he is the son of Baratheon and Cersie Lannister, according to Hollywood.
Melisandre tells Gendry his identity in the video clip below.