The season never really happened for the team's standout young catcher, who tore his right ACL during the second exhibition game a year ago. He had reconstructive surgery March 4 and spent the entire season rehabbing the knee.
"You can't take anything for granted. That's definitely something you learn from something like this, and how quickly it can be taken away from you," Castro said. "Realizing that all it takes is one play is something that makes you appreciate it more."
The 24-year-old Castro had surgery on his left foot in December, but he has been moving well in the early days of spring training. There is no visible evidence of an injury.
"Given the circumstances and the way things are playing out, I'm happy with where I'm at," he said. "The rehab process went as good as I could have hoped for."
Six weeks before opening day, the Astros are playing his return cautiously.
"Nothing is hindering him as far as pain or stiffness or soreness or anything else, but because he missed a whole year, we're going to monitor him and make sure he's not trying to overdo it," said manager Brad Mills. "He's doing all the drills, but maybe not to the extent or as long as the other catchers."
A first-round draft choice in 2008, Castro earned the Astros' regular catching job as a 22-year-old rookie in 2010. He was part of a young group of players who gave the Astros some hope in the second half of the season that year.
There was no such hope last year with Castro in a cast.
He was injured during the second game of spring training while trying to avoid a tag by Detroit Tigers first baseman Miguel Cabrera. he original diagnosis was a sprain, but an MRI revealed a meniscus tear in his right knee. A torn ACL was discovered later and operated on immediately.
As he rehabbed, the Astros went on to lose 106 games.
"We all saw how this ballclub played when he took over in 2010 as a rookie, how this guy took charge of our pitching staff. It was such a crushing blow last year to not get a game out of him," Mills said.
New general manager Jeff Luhnow said Castro is "critical" to the team's future.
"He's somebody who can be a leader and who can produce offensively and defensively and set the right tone for the entire team," he said.
By the end of 2011, the young catcher had gained confidence that his knee had recovered completely.
"I think a big part of that was playing in Arizona (in the fall league) and testing it out there," he said. "I was able to get past all the questions I had about how it would respond and how it would hold up. The strength is there and the comfortability is definitely coming back."
As for the recovery of the Astros, that will take more time.
"I was around the field a lot last year. Even though I wasn't catching guys, I was watching them pitch," Castro said. "I was talking to guys after their starts and things like that. As far as talking to pitchers and building that rapport, that never stopped. So hopefully we can just jump back into things and keep progressing on into the season."