It will be interesting to see. The fact of the matter is, Aaron Altherr may already be Lane Adams, or Sean Rodriguez, i.e., a usable but unexciting bench/depth piece. He's younger, though not (unless he clears waivers and the Phillies let him go) cheaper. Obviously a lot of people who have followed him for his whole Phillies career would like to think he can still return to the form he showed occasionally, but we're not likely to find that out on the Phillies major league roster this year, and even if he sticks around he is surely headed for a non-tender next year. But he's definitely still worth stashing in LV if that's what happens.
As for who would take his place, the answer is Herrera. The question then is do you still want to hold on to Altherr if he can't even get a start ahead of Rodriguez, or would you rather keep both Rodriguez and Gosselin? The reality is, Altherr is not better than either of them, and that's not just this year's SSS, it's last year's too. And they play more positions. With Herrera back, McCutchen showing he can play CF, and a greater need to find starts for Williams, I kind of think it's time let Altherr go, even without any expectation of Quinn returning.