Howard Stark may have a role to play in Avengers 4, with John Slattery reportedly said to have filmed a scene. Robert Downey Jr.'s Tony Stark has been the face of the Marvel Cinematic Universe since 2008's Iron Man. Audiences have had plenty of opportunities in 10 years to get to know the ins and outs of Stark. One of the most important aspects to him and a recurring theme is his relationship with his parents. He studied his father's work to discover a new element that saved his life, but then was driven for vengeance upon Captain America: Civil War revealing Bucky Barnes (Sebastian Stan) is responsible for their deaths.
Through the years, there's been three actors to play Howard Stark in the MCU. Gerald Sanders appeared through photos as Howard in Iron Man, but then John Slattery took over the role in Iron Man 2 and beyond. Only Dominic Cooper has played Howard since, but only for his younger adventures in Captain America: The First Avenger and Agent Carter. Slattery has been the more prominent portrayal and a recurring face in recent years.
The pattern of his appearances will reportedly continue in Avengers 4. According to That Hashtag Show, John Slattery filmed scenes during production on Avengers 4, which is the first sign that he is involved with the movie. There is no word on how large or small the role is, if true. The report does state that Slattery's scenes were with Robert Downey Jr. This is unconfirmed for the time being and may not be confirmed until Avengers 4 hits theaters if it is a small role. As a result That Hashtag Show cautions that Slattery's scenes could wind up on the cutting room floor due to the giant cast and possibly small role he has.
There's a few different ways Slattery could factor into Avengers 4. The least exciting option is it is just for a Stark or S.H.I.E.L.D. flashback of some kind. But, the first possibility that will really get fans' speculation wheels turning is through time travel. One of the most popular theories for Avengers 4 is that it's a time travel movie. If that is the case, then Howard could easily appear as Tony and the rest of the heroes jump around through time. One even has to wonder if Tony would try to find a way to stop their deaths in 1991 or at least give a proper goodbye to his old man.
The other possibility is Slattery appears through the use of Tony's Binarily Augmented Retro-Framing (or B.A.R.F.) technology. This is one of the ways that Slattery appeared in Civil War, and the Russo Brothers have teased that the tech may be a big part of Avengers 4 too. If Tony is searching his memories to try and find a way to beat Thanos, he may revisit some interactions with his father along the way. However Slattery makes an appearance, if Marvel Studios is working in characters this deep in the MCU rolodex, then Avengers 4 may have an even larger cast than some are expecting.
Source: That Hashtag Show