Mike Hart joined the team when he was drafted in the sixth round of the 2008 NFL Draft. What is alarming about Hart is that despite being the most productive running back in Michigan football history, he slipped to the bottom of the draft. It is somewhat rare for the best running back in the history of one of the most successful college football programs in the country to see his draft stock plummet to near irrelevance. The reason for Hart's plummet is his small size and poor performance in the NFL Combine. At only 5-foot 9-inches tall and 206 pounds he is considered too small to be a legitimate NFL starter. His 40-yard dash time of 4.67-seconds is much slower than the coveted 4.4-second time most teams look for in running backs. Still, a guy has to know how to carry a football to completely obliterate division I level competition in college. [caption id="" align="aligncenter" width="420" caption="Mark Duncan | AP Photo"]Mike Hart Highlights: HOF Game 2008 - NFL.com[/caption] The reason Hart has been so successful is both ironic and somewhat obvious, he has a lot of heart. At no time was that made more clear in his NFL career than when he carried the ball for two yards on a third-and-two against Baltimore in week six of the 2008 season, with 4:15 to go in the first quarter. Hart fought through multiple would-be tacklers, the first of which happened to hit him three-yards behind the line of scrimmage and allowed the Colts offense to stay on the field and eventually score the second touchdown of the game to put the Ravens down 14. Unfortunately for Hart, in the second quarter he would catch his first official pass in the NFL, make some nice moves and gain 12 yards, only to suffer a season-ending knee injury. After he returned healthy in 2009, Hart was called upon primarily for short-yard downs, both as a blocker and ball carrier. In that time he showed some of his shiftiness, some of his toughness, and a bit of that innate ability to generate yards in the most unpleasant of circumstances. Statistically Hart does not look like anything special, but his play on the field has given Colts fans a reason to be optimistic entering the 2010 season. If Hart continues to develop, after playing what amounts to one full season in the NFL, he could be a secret weapon moving forward. If either Brown or Addai has to miss any time, Hart could have his chance to break into NFL legitimacy. No one wants to see any of the Colts players miss time but if Hart is given more opportunities to run the football during normal game circumstances, he could be surprisingly effective. Hopefully fans will have another chance to see what Hart does in preseason play. Enjoy his preseason performance in the Hall of Fame game during the 2008 preseason.