Lewis at 1B - No. Total waste of his fielding development to put him here.
OF - No, don't want to risk an overzealous rookie getting hurt by crashing into a fence without at least some games out there at AAA. Plus, with Larnach back soon, Kepler, Buxton, Celestino, Larnach and Gordon have OF covered.
3B - Maybe. If they are going to play him 4 or 5 times per week here and 1 or 2 at SS each week. The Twins defense will be worse as Urshela is great at 3B and Lewis hasn't played there in years.
What will the Twins do? I say Lewis goes back to St. Paul, either when Correa comes back on Wednesday or when Correa is back to full-time, as I think he will get days off like Buxton.
Playing SS is the most fun and complex position on defense. If Lewis does play elsewhere this year, he will be making more errors there next year for the Twins so people had better be ready for that. As far as hitting, unless he gets in a big slump, it is better for Lewis to be seeing major league pitching. Tough call.