I wouldn't write Wilken off just yet. He has a .796 OPS over the last 28 days and had a .878 OPS in June. Only turned 24 back in June. The question is if he suffered permanent eye damage; he struggled early this year, was out of the lineup for a while in late May/early June, and then came back great in June. My guess is that he had more eye therapy done during that time.
The biggest question with that entire group is if any of them project to be good enough defensively to be an average ML 3B. Fischer will be given every opportunity to prove it, but from everything I've read it seems like he has a ways to go. For their careers, Wilken has 1850 innings at 3B, 550 at 1B, and 9 G at DH; Adams has 1680 innings at 3B, 970 at 1B, and 8 G at DH, so it seems that Wilken may be thought of as a little better 3B than Adams.
And Adamczewski needs to be added to the DH discussion. Not much room in the OF either.