By The Associated Press SAN DIEGO — The Colorado Rockies have placed pitcher Roy Oswalt on the 15-day disabled list with a strained left hamstring. To fill Oswalt’s roster spot Monday, the team recalled outfielder Charlie Blackmon from Triple-A Colorado Springs. Blackmon is in his second stint with the Rockies this year. He batted .240 (6 for 25) in 12 games earlier this season. Oswalt is 0-4 with a 7.64 ERA in four starts with the Rockies since signing a $2.3 million, one-year contract on May 2. The 35-year-old right-hander, a three-time All-Star with the Astros and the 2005 NL championship series MVP, went 4-3 with a 5.80 ERA in [...]