"It's a great league, and the competition is probably the best to prepare guys for the Major Leagues," said Castro, an All-Star last season in Houston. "It's a great thing to be a part of."
The Arizona Fall League, which takes place for six weeks from October through November, is considered a finishing school for some of baseball's top prospects. Castro, a first-round Draft pick by the Astros in 2008, went to the AFL in '09 and played for Peoria as an up-and-coming prospect.
Two years later, Castro played for Salt River to get some at-bats he lost when he tore his anterior cruciate ligament during Spring Training that year and was lost for the entire season.
"I had an opportunity to play with some really great guys," Castro said. "I think our team that first year, we had [Craig] Kimbrel, [Jason] Heyward, Freddie Freeman, a lot of those guys -- Mike Leake and Yonder Alonso. You get to see some of the rising stars that everyone talks about, and you get to play with them, and it helps you build some friendships that last whenever we go play those guys. You see those guys around and you build those relationships that last a while."
Fowler went to the AFL in 2007 while he was with the Rockies, playing for Peoria. He was coming off a season at Class A Modesto where he played in just 65 games before fracturing his hand. Like Castro in 2011, Fowler was making up for lost time.
"It gave me a chance to play against guys who had big league experience and just some guys you never ever seen coming out of High A, so it was definitely challenging," Fowler said. "I definitely had fun there. It was a good league."
Pat Listach, in his first year as Houston's third-base coach, didn't play in the AFL as a player, but he managed there twice. In 2001 and again in '06, he was at the helm for Mesa, helping develop Astros prospects Troy Patton, Hunter Pence and Matt Albers.
"You get players from five teams and you get to know the different players, you get to know other general managers, other farm directors, scouting directors," Listach said. "It's good to know these guys. It's a great league."