If it was a reasonable suggestion, they would have tried it by now. We've had negative production from third base since we traded for him and he's played 1/3rd of an inning there. We spent $6m on a hitter who can only play first base, sent our opening day third baseman back to Iowa, and opted for Nicky Lopez rather than moving Busch to third and trying any combination of Turner, Moises, Long.
And that's before considering that Moises Ballesteros, all 5'8" of him, has played first base one single time this year. He got called up to AAA last year on 6/15, played first base once in each of the first two series, and then just...didn't, the rest of the year, not once. Probably no reason!