With reports of Chris Evans possible return to the Marvel Cinematic Universe as Captain America, let’s inspect how the comics made an elderly Steve Rogers young again.
While Avengers: Endgame was the last film in Chris Evans’ role as Captain America for Marvel Studios, the film delivered a proper conclusion to the Steve Rogers’ story.
He lived a full life back in the past, only to reappear in the present as an old man, ready to pass on his shield, which he handed over to Sam Wilson as his successor, and became a leader of S.H.I.E.L.D.
In 2014’s Captain America #22, Captain America fought evil villain Iron Nail who then drained him of the super-soldier serum – causing his body to deteriorate rapidly into his supposed age.
It was in the 2016’s Avengers: Standoff! a crossover event that Rogers’ became his young super-soldier self again.
Old man Rogers joined the Avengers in a fight in S.H.I.E.L.D.’s secret town of Pleasant Hills, solely populated by brainwashed evil villains who regained their memories.
During his attempt to save Kobik, a cosmic cube shard disguised as a little girl, Crossbones attacked Rogers and brutally beat him up.
Just before Crossbones was about to finish him, Kobik then turned Steve Rogers back into his young super-soldier self with her reality-altering powers using her reality-altering abilities.
Steve Rogers was Captain America once more.
With that said, the Cosmic Cube in Marvel comics is none other than the Tesseract in the MCU.
In the comics, it was used to restore Steve Rogers’ super-soldier abilities by rewriting reality. As for the MCU, it was a space stone used to open a gateway to the cosmos.
Therefore, it’s highly unlikely that the Tesseract made Rogers young again in the MCU. But of course, that doesn’t mean there aren’t other ways to alter the Marvel reality.