Sure, there's the potential trade return to consider. But I'd argue that these sorts of "sign a guy for the sole purpose of dealing him to a contender at the deadline" signings fail far, far more often than they succeed. It's a low-risk move, so it's nothing to stress over, but it's rare for these sorts of guys to really play well enough to merit any sort of meaningful return.
It's conceivable that Gomes might smack around lefties for a few months and garner interest at the deadline. It's happened before. Realistically, however, it's exceptionally unlikely for a contending team to give up much of value for the short half of a corner outfield platoon, especially when the guy doesn't offer much defensively or on the bases. In the very, very best case scenario you probably get a guy who wasn't as good a prospect as Perez or Terdoslavich were in their minor league days.
Young...honestly, I don't think there's any realistic shot of converting him into something valuable. I agree he has his uses as the 24th or 25th guy on a playoff team, but those sorts are freely available talents, and most organizations have a player or two in the upper minors who can play multiple positions and run the bases. The best you can hope for in an EY trade is a PTBNL or cash considerations.
I haven't disagreed with any of this. The point I made is that we MIGHT get a little something for one or both of them if someone has an early injury. The one thing Terdoslavich has proven is that he doesn't appear to be much of a threat off the bench and that he needs consistent ABs to provide any production. We've already committed money to Gomes, and it looks more and more like we're going to take a bath on the money promised to Callaspo unless we carry two backup IFs who can't play SS.
I like Joey as much as the next guy I guess, but he's not good enough to be a starting OF at this level. Can he hit? Sure, when he gets regular playing time. However, he can't provide power, can't steal a base, and is likely a defensive liability anywhere other than LF or 1B (where he won't get ABs).
I'm pretty sure it's fair to assume that Smith is going to be sent down no matter what - no sense in starting his clock unless you're going to make him the everyday CF and have him lead off. That leaves you Perez and Cunningham as guys capable of handling CF defensively until Melvin returns. Assuming you cut EY, you pretty much have to carry both of those guys, so you're now looking at Markakis, Perez, Cunningham, Gomes, Almonte, and potentially KJ - all of whom offer things that Terdo can't (power, positional flexibility, ability to play CF, whatever).
It becomes even more complicated if we sign Olivera - he'll be the 2B until they can unload or release Johnson, meaning you've removed another potential leadoff option when you send Peterson down, and you more or less have no choice but to keep EY and Perez.
The return I personally would be asking for in ANY Gomes/EY/Callaspo deal would be international bonus slots anyway. There's a much better chance Hart & Company could turn that into a better prospect return we'd get for any of those guys, and we really don't need any more 4th/5th OFs or utility IFs than we've already got.