Detroit Lions cornerback Chris Greenwood is not second-guessing himself. Greenwood fully participated in Detroit's organized team activities (OTAs) this week with the goal of competing for playing time in 2013. He moved with ease on the practice field while covering receivers in practice. Greenwood was aggressive and not afraid to make mistakes. At 6-foot-1 and 193 pounds, Greenwood has the size necessary to cover big receivers in the NFL. Unfortunately, for Greenwood, this is coming a year later than anybody expected. Greenwood started to develop pain in his abdomen last offseason, but did not tell anyone because he was trying to make the team as a rookie. He tried to fight through the pain, but that omission aggravated the injury, and Greenwood was placed on the physically unable to perform list in late July. Greenwood, a fifth-round pick in 2012, eventually missed his entire rookie season due to the injury. As Greenwood attempts his comeback, he does not want to dwell on his decision to hide the injury from Detroit's coaches and doctors last year. "I feel like everybody plays through some pain," Greenwood said. "Everything happens for a reason. I didn't know it was as severe as it was until I actually got all the way hurt. It is what it is. I'm not regretting playing those few plays that I played with that injury." Greenwood proved he has heart. Now Greenwood must prove he deserves playing time. Greenwood had 24 tackles, two interceptions, and was named the Michigan Intercollegiate Athletic Association defensive player of the year for Albion as a senior. He was one of three cornerbacks drafted in 2012, but missed all of last season due to his injury. However, Greenwood spent most of his time with Lions coaches during practice in an effort to learn from the sidelines. "I don't feel like I'm behind," Greenwood said. "Last year, after I got hurt, I still came every day and got all the information, so I feel like I'm right with everybody else. Maybe not rep wise, but that's going to come with time."