I've never heard of him, but here's some info on him.
4th round pick in 2012 by Houston; 38 receptions 418 yards over 3 seasons
6' even 188 lbs 4.45 40, 6.85 3 cone
OVERVIEW
Martin is an explosive mover who is quick off the snap to work into his routes. He's been a two-year starter for Michigan State and has been productive running with the ball after short catches. He can take a bubble screen the distance and uses his pure athletic ability to outmaneuver defenders. He is athletic enough to be the superior guy on an NFL field matching up against most DBs. He is a very good speed-variance route runner who can keep corners on their heels and toes. He has fourth-round value and is such a late riser with a solid, productive Big 10 championship game that he could continue to rise into the late third round.
ANALYSIS
STRENGTHS Martin is good at varying his speed in routes. He is the type of athlete who can make ridiculous moves with his feet while still running full speed. He is explosive when moving off the ball and gets to top speed very quickly. This is usually how he dials up his routes, as he is into them before the corner is even ready. He uses this same foot quickness to get open at the top of routes. He has the speed to be a deep threat at the next level and is dangerous with the ball in his hands. He will work a lot of screens looking to get behind blocks of bigger receivers outside.
WEAKNESSES Martin is uninspired when it comes to blocking. Despite decent size, he isn't very strong and just looks completely uninvolved. The same can be said when going across the middle; he is unreliable with defenders draped around him and needs to be completely open to finish the play.
http://www.nfl.com/combine/profiles/Keshawn-Martin?id=2532900