Adam Dunn played 1B for the Nats. It’s not that difficult to learn to play it in a decent manner. I think the bigger issue is that Riley Adams is probably not a good enough hitter to justify him at 1B long term. Looks like a 4A guy.
Dunn could stand and catch a throw, mostly. And Riley Adams has played a few games at 1B in AAA. None of that is the way Hernandez, Mattingly, Ernie Banks, or our own Adam Laroche or Mickey Vernon played 1B. If Pineda returns, then, sure, demote Adams to play 1B with Rochester. Let him hit regularly. Otherwise, why assume that Adams, or any non-infielder, can play first?
Ernie is the best example of a conversion: All-star SS (and NL home run champ), he moved to 1B when he was 31. Can Adams field like Old Ern?, or, as Natsinpwc asks, hit like Ernie Banks?