He's a biiiiig guy but a very fluid athlete for such a big guy. He stands at probably around 6'5" 230 pounds on most days...but his body is built very much like Mike Williams, who was drafted top 10 overall. When I say that I mean he's got a long, lean wide receiver's body...not a bulky tight end's body. Marques Colston looks on the bulkier side and he's the same size as Marshall.
What is great about Marshall is that he's got very quick fluid hips for his size. He is innately strong, and if smaller corners try to bump him at the line they had better be prepared because at times he can quite legally just toss them to the ground because he's so big and strong.
Everyone likes to talk about speed but this guy can shift 1st through 4th gear the same as most of the guys who are smaller and are supposed to be much faster. In fact, some might say his 2nd gear is near the top echelon of receivers. The problem is when he needs to shift into 5th gear, he just doesn't have it. Some have claimed he ran a 40 in the 4.4's and I am not sure I believe that. He ran about a 4.50 from accounts I've read, maybe a little bit slower. The thing to note is that although his top gear just isn't there compared with say, the top gear of a Chad Jackson, his first couple of gears are there, evidenced by his solid 10 and 20 yard splits.
In the tapes you'll notice that the deeper the route, the more time the corner has to catch up to Marshall. But that often won't matter because if it's a high ball Marshall's going to pluck it out of the sky and there's usually not much a corner can do about it. Also, as a junior the golden knights suffered so many injuries in the secondary that he became their starting safety, and led the team in tackles. His experience in the secondary seems to have helped him understand some concepts on offense better on how to hurt a defense. As a result he does seem to have a good feel for finding the holes between zones.
It's tough to say where he should go. He's fast for his incredible size but he's not lets say, Matt Jones freak of nature fast. He's great going up on jump balls and I doubt many corners would want to bump him at the line. If you believe TerryTate, he overheard a Patriots scout at Marshall's pro day workout mention the possibility that they take Marshall in Round 1 even. I'm not sure how much I believe that, whether the scout was purposely saying that aloud to have people overhear it, or whether he was referring to Richard Marshall of Fresno State. Either way I have Marshall among my top 10 WRs in the draft and I think he's a solid round 3 pick.