Darin Ruf made a rehab start last night in Clearwater, the last of the Phillies reinforcements from the injured reserves to do so. That puts a lot of pressure on Ruf, who has never played a full season or produced consistently at the Major League level.
Presuming the "Darin Ruf is an Outfielder Now" experiment remains a chilling, but closed, chapter in Phillies history, there's only one position that makes sense for him (As was the case when he was trying be an outfielder): first base.
As Matt Gelb points out, the Phillies first base slash line is 13th in the NL in all three categories: .226/.292/.395. Ruf was projected by Fangraphs to slug around .407 and forge an OBP of .316 this season in a limited number of at-bats. This spring, he went 10-for-46 with five walks before straining his oblique. Last night in Clearwater, he went 0-for-3 with a strikeout.
Ruf is no savior, but can he contribute in any helpful manner? The bench, while rid of Freddy Galvis for the moment, remains weak. Ruf is more of a power option who isn't worth much defensively, much like Ryan Howard. Sending him back down to triple A isn't going to do him much good, other than get him at-bats at a level where it is already known he can hit.