The most important job for NFL coaches and GMs is figuring out which 2007 draft prospects will contribute significantly and immediately. It's fun to speculate over whether JaMarcus Russell or Brady Quinn will go first overall, but history has shown us that it's likely that neither of them will start immediately, and even if they do they aren't very likely to be any good for several months. Or years. The players who play well immediately will be far more important, because they will be factors in early games, and they will impact effective handicapping decisions for those games. Imagine, for example, if you had had a good sense that Marques Colston was going to be as good as he was before the season started. Here's a look at eight likely first round players who could hit the ground running and change games by their presence:

Some 2007 draft prospects that can make an immediate difference:

Calvin Johnson, wide receiver, Georgia Tech - Johnson is an absolute freak. He's probably the most impressive player in the draft. He put up incredible numbers during his time at Georgia Tech, and he did it all while playing with a truly inept quarterback in Reggie Ball. With a quarterback who actually has the ability to pass the ball Johnson could be truly special. He'll obviously go to a team that needs help on offense, so he'll get a chance to start early on, and he'll see the ball. First round receivers are traditionally hit and miss, but Johnson seems as close to a sure thing as there is. As long as he doesn't get drafted by Detroit, that is - that team can destroy any good receiver.

Alan Branch, defensive tackle, Michigan - Having Branch in the middle of your defensive line is like having a brick wall built on the line of scrimmage. The guy is huge, and he is a menace. Michigan was, except for their late-season collapse, dominant against the run, and Branch was the biggest reason. There are a lot teams out there that can't stop the run at all, and Branch can step in and improve any of them immediately. He is the best defensive player available.

Joe Thomas, offensive tackle, Wisconsin - Thomas is the best tackle prospect we have seen in several years. The last Big Ten tackle superstar, Robert Gallery, has been a little disappointing as a pro. Thomas, though, comes into the NFL looking perhaps more impressive than Gallery did. He'll get drafted by a team that needs his help, and he'll almost certainly get a chance to start right away. Even if it takes a while for him to adjust he'll still be an upgrade at an important position for his new team.

Adrian Peterson, running back, Oklahoma - In terms of talent, Peterson is as good a pure running back prospect as we have seen in a long time. The only cause for hesitation is his durability - he has been hurt more than he should have been in college, and the pro season will obviously be longer and tougher than what he faced in Norman. There is a limitless need for running back talent in the league, and Peterson could put up some serious numbers for a team that badly needs his help.

Gaines Adams, defensive end, Clemson - If Alan Branch isn't the best defensive player on the board then Adams is. He's an incredibly athletic end who could rush the passer as well as anyone in college. He's small and fast enough that he could easily drop back to outside linebacker in a 3-4 defensive scheme. He needs some work on his run defense, so he won't be an immediate every down player in the pros, but he will make a difference when he is on the field.

Darrelle Revis, cornerback, Pittsburgh - Over the long term Revis may not be the best corner in the draft - Leon Hall has the inside track on that distinction - but he is the most polished and ready to contribute right now. If he falls far enough in the draft that he is chosen by a team that already has a decent DB or two so he doesn't have the pressure to be the immediate first choice then Revis has the potential to put together a very solid rookie campaign.

Ted Ginn Jr., wide receiver, Ohio State - Did you see what Devin Hester did on the opening kickoff of the Super Bowl? How about what Ginn did on the opening kickoff in the BCS Championship Game? Hester showed the game-changing impact that a speedy rookie can have all season, and Ginn brings tools to the table that are at least as good as Hester's. Ginn doesn't even have to contribute anywhere other than special teams to be valuable, and he has the ability to contribute in many more ways than that.

LaRon Landry, safety, LSU - A lot of teams need defensive help. In terms of first round talent, this is not a great draft for linebackers. A team that is looking for a linebacker, but doesn't want to convert a defensive end, or doesn't use a 3-4, would probably be better served by looking further down the field to safety. Landry is probably the best available safety. He is very good in coverage, and he is a valuable contributor to run defense. He will have to add some more muscle at the pro level, but he has a body that can handle that.