How long does it take for a former prospect to regain his status?  How significant is age against a prospect when the extra years are lost not to middling performance, but to injury?

The guy who brought this question up for me is Matt Antonelli.  As most of you probably know, he is a former 1st round pick (17th overall, 2006) of the Padres.  He was drafted out of Wake Forest, signed quickly and progressed rapidly through their system in 2006 and 2007.  His progress up through AA ball at that point had Sickles rating him as a B+ prospect and the #2 guy in the Padres system with a good glove, solid bat and good strike zone judgment but questionable power (I'm guessing the latter is why the Padres moved he from 3b to 2b). 

But Antonelli fell off the table in 2008 (although he did get a cup of coffee with the Padres that year), going from a .294/.395/.476 in AA in 2007 to .215/.334/.322 in AAA in 2008.  His numbers didn't improve in 2009 (.196/.300/.339) and after 54 games he was shut down with wrist pain that could not be diagnosed and didn't respond to cortisone shots.  He was finally diagnosed with a broken hamate bone and underwent surgery in April of 2010.  According to his web site, he had been experiencing severe wrist pain for two years.  If true, it's no wonder that his batting and power numbers vanished (his batting eye remained solid even when he couldn't hit).  The Padres cut him last December, and the Nationals picked him up for a song.

And, with the surgery (and the wrist pain) behind him, his bat is back.  Over 88 games and 369 PA - all but 4 and 15 at AAA Syracuse - he has slashed .299/.393/.463 in 2011, posting the best OPS on the team.  He looks a lot like that guy that Sickels rated a B+ entering 2008.  His strike zone judgment is still good (58K, 49BB in 354 AAA PA), but with marginal power (19 2b, 3 3b, 8 HR).  It's clear to me that Antonelli has turned a corner, but even though he's done very well at AAA it's not at all clear where the turn leads.

Understand that I'm not touting Antonelli as a great prospect at this point; I'm guessing his ceiling would be a solid middle infielder/unspectacular #2 hole hitter, with the most likely role being that of a utility guy (he has played 2b, SS, 3b and a little bit of OF in Syracuse).  Right now he's a better story than a prospect; I'm happy for him that he can now say "hey, I could play" instead of just vanishing into baseball obscurity.  But is it enough to make him a prospect?  Is he "back" to a ratable prospect?  Or even a "person of interest?"  Unless there's a trade in DC it's hard to see him starting at the big league level, since the Nationals have a plethora of middle infield types (Espinosa and Desmond starting and Lombardozzi and recent draftee Anthony Rendon - with Zimmerman blocking him at 3b - on deck).  Antonelli just turned 26 in April, and given that he has essentially lost three years to injury rather than suckage I think he’s earned an invite to the major league camp and a chance to compete in 2012 for the Jerry Hairston/Alex Cora utility role on the Nats no matter what happens in the middle infield.

Your views on what it takes for a former prospect to be "back" in general, and on Antonelli in particular, are welcome.