The second-year defensive tackle hadn't played in a game since he helped the University of Alabama win the national title in January 2012.
Chapman was finally on the field during the Colts' preseason loss to the Buffalo Bills on Sunday.
"It felt pretty good," Chapman said. "I got a little nervous about it but at the same time, when I got the first pop it was back to normal. ... Every day it feels better and better, more punch on it and just cutting on it, it feels great."
Chapman was the Colts' fifth-round draft choice in 2012, but missed all of last season with a torn ACL, which he played with most of his senior season at Alabama.
Chapman's numbers weren't eye-popping against the Bills -- four tackles -- but all that matters is the "900-pound safe in the middle of the line of scrimmage" is back playing again. Chapman has the size -- 340 pounds -- to clog the middle of the line and draw multiple blockers to him, which will open things up for his teammates. Chapman is behind Aubrayo Franklin on the depth chart.
"I think Josh is a bigger-bodied guy," Colts defensive coordinator Greg Manusky said. "He's got a great amount of weight behind him. ... He's a little sore, which is expected, but he did a fabulous job for us."
Other camp highlights Wednesday:
A day after dropping at least four balls, receiver Darrius Heyward-Bey made up for it Wednesday when had he one of his best practices at camp, catching two touchdown passes from quarterback Andrew Luck. The Colts need Heyward-Bey to produce like that on a regular basis.
Manusky said he'd like for the starters on defense to play about 15 plays in Sunday's game against the New York Giants. "It depends on how old they are, too," he said. "You get the 30-plus guys like Cory [Redding] and Aubrayo and Robert [Mathis], it's a little bit different. You kind of want to take care of them a little bit."
In a move that had the defensive players pumped up during a pass-rush drill, Mathis had tackle Anthony Castonzo convinced he was making a high outside move, but then he suddenly spun in the opposite direction to get to the quarterback dummy. Fellow defensive lineman Cory Redding ran over to Mathis and started dumping water on him to cool him off.