Moving from a more difficult infield position (SS, 2B) to a less demanding one (1B) should not be too hard. You see veterans doing it after they get older and lose their range, like Pete Rose, Rod Carew, and Miggy Cabrera, who played over 3,200 innings at third base.
Tito said he saw Nolan Jones playing some first base and he looked really good. These guys already know how to field ground balls.
It seems to me it's very significant that they have Miller playing some first base in Columbus. One, they want to get his bat into the Indians' lineup ASAP. Two, they can't play him at second or third for obvious reasons and apparently he's not a major league shortstop. Three, Chang and Bauers are hitting something like .125 between them and Bradley is 1-for-16 with 7 K's.
They could stay with Naylor at first but that puts Harold Ramirez in center and I don't think they want him there any longer than necessary. I think they would rather move Naylor back to right field and Luplow to center. Miller is 7-for-15 at Columbus. As soon as they think he's comfortable at first base we may see them make that move.
It could also depend on if Harold keeps hitting and if Luplow continues to hit .175. I would not be surprised to see Gamel get another shot. Amed Rosario hits lefties extremely well. They could platoon Amed and Gamel in center and Naylor and Luplow in right. Miller would play first base and Harold would be the odd man out. Gimenez plays short every day and they make him bunt against lefties and shorten his swing against righties. He tries to hit home runs too much.