I actually see potential in Henderson, but he's nowhere close to where De Gea is right now. Maybe in 2-3 years, but not now. Fukking hell we'd deserve our miserable fate if we ditched De Gea for Sa.
Maybe an illustration might help. Let's say you, JB7, has underling medical conditions such as diabetes as well as an ingrown toenail, but you're being rushed to the ER because your car got smashed into on the road with you sitting in it. The ER medics have got to take care of the brain trauma first or else you're finished. Once you're out of the ICU you can start taking medication for your diabetes and get that ingrown toenail taken care of, but not until you're out of the ICU. We're in the ICU right now.
Any serious observer of Manchester United this season will acknowledge that the De Gea was in nowhere near close to being the most pressing problem in the squad, and in fact he was arguably our best player this season -- some would say Ronaldo, but no one would say someone other than De Gea or Ronaldo -- and when you break it all down by player apart from De Gea and Ronaldo, to a man we were pretty fukking shambolic most of the season. Fullbacks, shit. CB's, for the most part shit. McFred, shit. Pogba, shit. Lingard, shit. Bruno, not quite shit but almost. Rashford, shit. Sancho, ok at best. Ronaldo had some incredible moments but the end of his career is coming quickly. Apart from Garner our players on loan don't look all that promising. We've got a lot of problems to deal with first, which will eat our transfer budget quickly, before we should even think about ditching De Gea.
Fix the crisis to the patient first, then fix the ingrown toenail.