Foggy Nelson, the long-suffering best friend of Matt Murdock/Daredevil, is the latest addition to The Defenders miniseries event. The series is set to link all of the Netflix-Marvel shows: Daredevil, Jessica Jones, Luke Cage, Iron Fist in a way similar to the buildup to The Avengers. Just as that was an ambitious project in the movie landscape, this too will be an ambitious project in the television landscape. The shows are all filmed at different times and other than sharing a head producer in Jeph Loeb, each show is independent of one another. The Defenders is being run by the same creative forces behind the second season of Daredevil. So it only makes sense that Daredevil's best friend would also join the show.
Earlier in the year, it was reported that Malcolm Ducasse, the addict turned Jessica Jones confidant, was also joining the cast of the show. So while The Defenders is also bringing the heroes together, it is also bringing their major supporting characters along with them. This makes sense as the two reported supporting characters are so intricately tied to the heroes and their events, they would come along with whatever is going to happen on this show. Since Luke Cage and Iron Fist have yet to premiere, it is hard to say who will join them in The Defenders.
There is one major candidate who can help tie all of these people together. Whether it be the heroes to the supporting characters. That character is Jeryn Hogarth. The character first appeared in Jessica Jones and made a cameo in the very last episode of the second season of Daredevil. There she offered Foggy Nelson a lucrative job within her firm and he had no reason not to take it. So there are two links together. Though Hogarth never met Malcolm, he seemingly became Jessica's secretary by the end of the first season and no reason to doubt that they have met one another by the events of The Defenders. Hogarth was also announced months before that she would be appearing in Iron Fist.
It is important to note that in Hogarth's appearance in Daredevil, she seemed to want to hire Foggy because of his familiarity with "people with complexities." During the events of Jessica Jones, she learned the effects of people with powers and how dangerous (yet useful) they can be. Can Hogarth be one of the key links in bringing all of the heroes together? That probably won't be answered until the events of Iron Fist play out, but Hogarth is shaping up to be an important person in the Netflix side of the Marvel Cinematic Universe.
Watching the upcoming series such as Luke Cage and Iron Fist, it's going to be key to watch which supporting characters might be used for The Defenders. Luke Cage has characters such as Misty Knight who is an important figure in Marvel Comics. Iron Fist's cast is still unknown at this point so time will tell. There is also The Punisher who was introduced in Season 2 of Daredevil and someone who is still out there. The Defenders is expected to be released in the latter half of 2017.