Inbox: When will top prospects arrive?

It looks like the Padres have turned their focus toward the future. Which prospects are expected to debut this season?
-- Peter
Tyson Ross and Jordan Lyles are off to the National League Central as waiver claims. There's never been a clearer message that the Padres are turning toward the future and ready to give some of the talent in the their top-ranked farm system a chance.
For now, that means Brett Kennedy and Trey Wingenter get their callups. It also portends further moves in the not-so-distant future. Barring injury, Luis Urias and Francisco Mejía will almost certainly join the Padres over the next two months. (It's technically not a big league debut for Mejia, who had 18 plate appearances with Cleveland).
After Mejia and Urias (ranked third and fourth in the Padres system, respectively), Jacob Nix could earn the call as well. He'll need to be placed on the 40-man roster ahead of December anyway, or risk being exposed to the Rule 5 Draft. For that same reason, the Padres might be hesitant to promote right-hander Cal Quantrill or left-hander Logan Allen. With sparse room available on the 40-man, neither needs to be added until after next season.
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How would Austin Hedges and Mejia coexist on a Major League roster? Who would get the most playing time?
-- Terry, Costa Mesa, Calif.
All along, the Padres insisted the Mejia trade wasn't a knock on Hedges' talent. They merely had the chance to land the game's top catching prospect, and they weren't about to pass up that opportunity.
Now, it leaves them with something of a long-term conundrum behind the plate. The Indians toyed with moving Mejia to the outfield. The Padres have no such plans in the immediate future. But ultimately, don't be surprised if Mejia gets some work in the outfield next spring.
If Hedges and Mejia are the team's two catchers next season, it's a safe bet Hedges' playing time will decrease. The Padres aren't going to put Mejia into a strict backup role. But Hedges will remain their No. 1 catcher, playing at a pace of something like 110 games. In theory, Mejia could catch the rest, while playing some outfield as well.
Who is the odd man out in the outfield going forward?
-- Justin, San Diego
That's what the rest of the season -- and possibly next season -- is for. The Padres are almost certainly going to add to their rotation, their bullpen and probably their infield. But it's hard to envision them signing an outfielder, given the logjam we're already seeing there.
Wil Myers is the left fielder (though it's possible he adds third base to his repertoire). Manuel Margot is the center fielder. After that, it's going to be a battle for playing time, and the Padres are fine with that. Hunter Renfroe, Travis Jankowski, Franmil Reyes and Franchy Cordero (who should return from a bone spur in his elbow for the start of next season) are all candidates.
The Padres have no problem moving forward with multiple options for one spot -- especially given the left-right platoon splits of all four hitters. It's probably better that they don't need to rely on one guy. But over the next couple months, I'd guess we see Renfroe playing regularly. It's his early chance to stake a claim for the starting job in right field next season.
Will Cory Spangenberg play shortstop this year? What is the plan for him?
-- Mike, San Diego
The Padres aren't going to make Spangenberg their shortstop of the future. Put simply: He isn't a shortstop. But there's inherent value if Spangenberg can play the position adequately as a backup. The Padres don't have a true backup shortstop on their roster. And it's unlikely they attack next season the same way they attacked this one -- with one player (Freddy Galvis) starting every game.
Spangenberg has been taking grounders at shortstop regularly during batting practice. There aren't any imminent plans to move him there, but here's why it makes sense to give him a shot either late this season or next spring: Utility pieces are much more valuable when they have "shortstop" on their resume.
Spangenberg has already proven he can play the outfield, along with his regular time at third and second base. He brings speed off the bench and a decent bat against right-handed pitching. If Spangenberg can add shortstop, that makes him immensely more appealing as a long-term roster option. I suspect we'll find out whether he can handle that position in the very near future.