It looks like the first-year manager was right.
Castro hit a two-run homer in the third inning to push the lead to 5-0, and added a solo shot in the seventh to make it 8-4.
"The rest that we've been able to give him I think is paying big dividends this time of year," Porter said. "Had he not had the amount of time off he's been afforded this year, I think you'll start to see the wear and tear a little bit. But I think he's going to take strong throughout the course of the year because we've done a tremendous job of monitoring his workload."
Brandon Barnes gave Houston an early lead with a two-run double in the second inning.
The Astros jumped on Chien-Ming Wang (1-2) for four hits and five runs in three innings in his first start since July 2 after his contract was selected from Triple-A Buffalo earlier in the day.
"Houston built a 7-0 lead before Toronto got anything going on offense. Kevin Pillar hit his first career homer on a three-run shot in the fifth inning and Edwin Encarnacion had a solo homer in the sixth for the Blue Jays.
However, Toronto's rally came up short as it tied a season-high with its seventh straight loss.
"It was a tough go for him," manager John Gibbons said of Wang. "He threw some good sinkers, but a lot of them were flat, and that was what they caught up. We fell behind early. It turned out to be too much to overcome."
Castro, who finished with three hits, has 17 homers this season, which ties a team-record for home runs by a catcher set by John Bateman in 1966. It was the third multi-home run game of his career and the second this season.
He said it was "surreal" to match the record, but that he thought he would be in for a good season after a productive spring training where he made some adjustments to his hitting.
"The biggest thing that I've really been trying to do this year is stay as consistent as possible and really not deviate from my approach," he said. "I've tried to be as simple as possible and it's worked out so far."
Castro doubled to start Houston's second and advanced to third on a one-out single by Brett Wallace. The Astros took a 2-0 lead on Barnes' two-run double.
L.J. Hoes walked in the third inning before Castro hit his 16th homer to the seats in right field with one out to make it 5-0. Right fielder Rajai Davis climbed up the short wall in vain to chase to ball as it sailed out of his reach and into the stands.
Barnes reached on a second error by Reyes with no outs in the fourth. Robbie Grossman extended his hitting streak to a career-high 11 games with a two-out RBI double before taking third on a passed ball.
Hoes pushed the lead to 7-0 when Grossman scored on his double to the wall in right field.
Peacock yielded a double to Brett Lawrie to start the second inning before retiring the next six batters. Encarnacion walked to start the fourth, but Peacock got out of the inning with a double play.
Peacock allowed consecutive one out singles to Anthony Gose and Ryan Goins before the homer by Pillar cut the lead to 7-3. The hit, which bounced off the wall in left-center field, was originally a double, but it was reviewed and ruled a homer.
Pillar smiled before trotting to home plate where umpire Bill Miller was waiting to hand him the ball.
Encarnacion got the Blue Jays within 7-4 when he homered for the second straight game to start the sixth.
J. P. Arencibia's RBI double made it 8-5 in the eighth.
Wang was making his second career start against Houston and the first since tearing ligaments in his right foot running the bases when he pitched as the ace of the Yankees' staff and faced the Astros on June 15, 2008.
The Blue Jays recalled RHP Chad Jenkins from Double-A New Hampshire and transferred INF Maicer Izturis, out with a sprained left ankle, to the 60-day DL. Jenkins allowed three hits and three runs in four innings. ... Houston Texans GM Rick Smith was a guest of Porter at batting practice before the game. "It was a natural connection and our friendship just has developed more and more as time went on," Porter said. "He's a huge supporter of mine and I'm a huge supporter of his." Smith said he has enjoyed watching Porter's work in his first year as manager. "He's such a leader," Smith said. "Obviously there's not a whole lot of success happening in terms of wins and losses, but what he is building here is so impressive. To watch him each day come to the ballpark with such a positive outlook and where he's leading this group is just impressive."... The Astros announced LHP Erik Bedard will be moved out of the rotation and into the bullpen. Porter said they'll announce his replacement in the rotation early next week. The 34-year-old Bedard, who had never pitched in relief in his career until a stint earlier this season, wasn't too happy about the move. "I was very surprised," he said. "I don't really know what to say."