When assessing the Patriots’ recent run of success in the seventh round of the draft, it’s clear they employed a similar approach last month with defensive end Michael Buchanan, who has the tools to be another success story. Buchanan had as high as a third-round grade, but his baggage from a couple incidents at Illinois caused his fall. That’s similar to cornerback Alfonzo Dennard in 2012 and defensive lineman Brandon Deaderick in 2010. The Pats also nabbed quarterback-convert Julian Edelman in 2009, eyeing a talented athlete with an impending learning curve. While teams want their first-rounders to be franchise cornerstones, they simply hope seventh-round picks can earn a spot on the roster. The Patriots, who perennially field one of the league’s deepest teams, have the luxury of using their late selections on players with higher ceilings but who had enough concerns to force their fall. Buchanan had two issues in college, a DUI in 2011 and a fight in the summer of 2012, which led to his jaw being wired shut, a loss of 20 pounds and a drop in performance. Keith Gilmore, who was Buchanan’s defensive line coach all four years at Illinois, thinks Buchanan has seen the light after a couple of immature decisions. “It’s college, and sometimes we don’t make the best choices,” Gilmore said. “To make a long story short, he’s a good person. He’s a good kid. I think these incidents have helped mature him. I shouldn’t say I’m glad, but it’s better that it happened now than later, and I think it just woke him up a little bit as to what’s important in life, just to take this whole experience of being able to be an athlete at this level, take it a little more serious and understand that it can be taken away from you. “I think those incidents have helped him and should help him grow and mature as a man.” Initially, Gilmore didn’t think Buchanan’s weight loss hurt his 2012 season, but, in retrospect, he knew it didn’t help. Buchanan’s greatest struggle was the departure of defensive end Whitney Mercilus, who led the nation with 16 sacks in 2011 and became a first-round pick. Mercilus captured the brunt of the offense’s attention, which allowed Buchanan to thrive. He had 7.5 sacks and 13.5 tackles for a loss as a junior, but dropped to 4.5 sacks and seven tackles for a loss as a senior.