Prior to this year, if you’d heard of Joaquin Arias at all, you probably knew of him as “the guy the Rangers selected instead of Robinson Cano.” The story is practically cliché by now: the Rangers traded Alex Rodriguez to the Yankees for Alfonso Soriano and a player to be named later. The list of PTBNLs consisted of five players, including Arias and Robinson Cano. Because he was two years younger and considered a better defender, the Rangers picked Arias over Cano.

Seven-and-a-half years later, Cano has won a Rookie of the Year award, a Gold Glove, three Silver Sluggers, and a Home Run Derby while posting a 30.9 WARP. Arias, meanwhile, sustained a shoulder injury in 2007 from which he’s never fully recovered and was eventually traded to the Mets for Jeff Franceour (cruel fate!). Released by the Mets, he was picked up by the Royals, and Arias spent the entire 2011 season in Triple-A Omaha, who designated him for assignment the following December. Thin up the middle, the San Francisco Giants signed him to a minor league deal for the 2012 season, and it wasn’t long before they needed him: Arias has been with the big club since late April, and while he hasn’t magically turned into Robinson Cano, he’s been far better than PECOTA predicted and pretty damn good for a guy who’s career should be over.

When he was coming up in the Rangers’ system, Arias was considered a very promising prospect. After all, the very smart people in the Rangers’ front office picked him over Cano.

“Arias looked like a premium defender at a premium position, and the bat was going to be full of contact, at the very least,” says Jason Parks, who saw Arias a lot in his time covering the Rangers. “The total package could have been a 7-plus defender, and those don't grow on trees.”’s Jason Cole concurs: “Arias looked like a potential Gold Glove caliber shortstop with speed and a hit tool. The bat was always seen as more of a luxury, though. Arias was a fantastic defensive shortstop… his arm was probably a 70-grade tool before the shoulder injuries.”

We don’t know a lot about the injuries; Arias himself either doesn’t know exactly what happened or is just cagey when asked. “The shoulder tightened up on me after the surgery,” he told me. “It didn't get stretched. But everything's fine now. The shoulder feels great.”

What we do know is that this promising prospect with a plus arm sustained an injury, underwent debridement surgery, and has never been the same. “For a period, Arias was completely unable to get the ball to first base (from short) unless he had all of his momentum going in that direction,” says Cole.

Even when he throws across the diamond now, he puts his entire body into the throw and follows the ball, wringing every newton he can out of his compromised shoulder. I asked him if he made other adjustments to make up for the loss of arm strength. “The only adjustment is that I work, I lift weights, I stretch and strengthen the shoulder. I feel that slowly, slowly, the strength is coming back.”

Arias’ journey toward league average began last year in the Dominican Winter League. He flat-out demolished Dominican pitching to the tune of a .387 average—more than 50 points higher than Alexi Casilla, the league’s next-best hitter. He also slugged .480, good for fourth-best in the league. That was enough to garner interest from at least a half-dozen teams. Arias’ agent urged him to sign with San Francisco because he felt the Giants were going to give him an opportunity. Arias kept hitting in the Cactus League, putting up a .298/.346/.447 line and leading the Giants in games played.

“He should have made the team out of camp,” Giants hitting instructor Hensley Meulens said. “He was that good in spring training.” Arias didn’t head north with the Giants when they broke camp, but he’d make the journey soon enough.

At the end of April, Brandon Crawford, the Giants’ everyday shortstop, was struggling. His batting average was hovering around .200, and he was playing inconsistent defense. Arias was called up to spell Crawford, and he got a much bigger role when Pablo Sandoval fractured his remaining hamate bone. Sandoval missed 35 games; Arias started 32 of those (27 at third base). Arias’ ability to play three infield positions made him especially valuable. The biggest change from previous years, however, is the modest power he’s displaying.

So far this season, Arias is sporting a .125 ISO, which is even better than he managed at Triple-A Omaha in 2010. When asked about the improvement, Arias shrugged. “I show up ready to play every single day. I'm ready to compete.”

Hitting coach Meulens was more specific: “We've talked to him about not letting the ball get so deep on him, because then he can’t use his strength. He’s wiry-strong and he's got the ability to hit the ball to all fields, but we told him to stand tall and turn on the ball.”

Meulens also suggested that a nagging hand injury, sustained when Arias was hit by a pitch in mid-May, was bothering him more than he let on. “He was playing with his hand hurt, so he was trying to hit everything over there because he couldn't really turn on it. But now all that inflammation is out of there, and we've talked to him about attacking the ball and not letting the ball attack him.” His spray chart certainly seems to agree: Arias seems to have far more success when he’s able to take the ball to left and left-center.

Arias still doesn’t walk—he’s drawn a base on balls just 12 times in roughly 300 plate appearances this year—but his defensive flexibility, his newfound (or rediscovered) power, and his .320 average vs. left-handed pitching all add up to a 1.1 WARP. He’ll never achieve the ceiling he had pre-injury, but his performance this season almost certainly assures that he’ll have a big-league job in 2013. Not so bad for a guy who was basically left for dead after 2010.

No story about Joaquin Arias would be complete without mentioning his role in Matt Cain’s perfect game. While his 5-3 putout of Jason Castro wasn’t nearly as sensational as Gregor Blanco’s diving catch in the 7th, it might have been as dramatic:

Castro hits the ball sharply and just to Arias’ right, so he moves to his right while giving ground. He comes around the ball and stumbles slightly—his footwork, usually so smooth, betrays him. Maybe he’s bending under the immense responsibility; maybe it’s just chance.

His momentum is carrying him away from first base, so he can’t step into and follow the throw, as he usually does. His right arm comes over the top, snapping like a whip as he releases the throw, straight and true to Brandon Belt, who comes off the bag in celebration almost before he receives it. A perfect game.

Arias smiles broadly when I ask him about the play, even before our interpreter has a chance to relay the entire question: “I can't really explain it except to say that it was a very special day. I didn't think the ball was going to be hit my way, but it was, and I was able to make the play.”