Avengers: Endgame may not be Robert Downey, Jr.'s last appearance in the Marvel Cinematic Universe after all.

Deadline reports Downey's Tony Stark will make a cameo appearance in the upcoming Black Widow movie, which takes place after the events of Captain America: Civil War.

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Another report from the Marvel Stuff Twitter account claims Downey's return as Tony Stark will be a short cameo using deleted scenes from Civil War.

Of course, all of this information should be taken with a grain of salt until Marvel Studios offers official confirmation. Even though Black Widow takes place in the MCU's past, it still doesn't mean the studio has plans to insert Tony Stark into the story's narrative.

Avengers: Endgame won the Best Comic-to-Film award at the 45th Annual Saturn Awards Friday night in Los Angeles. Downey also won the Best Actor award in a film for his role as Tony Stark/Iron Man in the fourth Avengers film, with Iron Man sacrificing himself to stop the Mad Titan Thanos.

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Directed by Cate Shortland, Black Widow stars Scarlett Johansson, David Harbour, Florence Pugh, O-T Fagbenle and Rachel Weisz. The film arrives in theaters on May 1, 2020.