"It's been feeling really good, especially the past week or so," Castro said. "After I got through that first series back off the DL, it's actually felt probably the best it's felt all year."
Castro went on the disabled list July 8 with right knee effusion. He had the knee drained July 18 and returned to the lineup in Chicago on Aug. 13. In nine games since returning, Castro is batting .286 (8-for-28).
Castro and veteran catcher Chris Snyder have been alternating games at the position for the last week.
Over the final month of the season, Castro is looking to improve both behind the plate and at the plate. He wants to continue to build relationships with the Astros pitching staff, especially with the new guys.
The postseason may be out of reach, but Castro will cherish the remaining 33 games after missing the entire 2011 season with a torn ACL in the right knee.
"It's really important for me," Castro said. "Having missed all of last year, it's just getting as much playing time as I can."