It's good to be fast. Just ask Titans RB Chris Johnson.

After running a 4.26 40-yard dash at last year's NFL Scouting Combine, the stock of Johnson, a relatively unknown player out of East Carolina, shot up to first-round level. And when he quickly became a fantasy stud by rushing for 1,228 yards and nine TDs as a rookie, Tennessee's gamble of a pick became more than justified.

Although the 40 is just one small measure of a player's football ability, a few guys in the 2009 class might have similarly boosted their draft status by running sparkling times over the weekend. Leading their respective positions in the 40, WR Darrius Heyward-Bey, TE Jared Cook and QB Pat White have the pure speed to be fantasy threats from Day One.

Nobody at the '09 Combine had more impressive straight-ahead speed than Heyward-Bey, who clocked in at 4.30 in the 40. That time tied the Ravens' Yamon Figurs for the fastest 40 of any receiver in the past six years. But unlike Figurs, who is a tiny 5-11, 175 pounds, Heyward-Bey measured in at a terrific 6-2, 210 pounds. The 40 isn't everything, though, and teams might be scared off by D.H.B.'s lack of production in three seasons at Maryland. So what should fantasy owners make of this?

Well, Heyward-Bey's mediocre college stats were partly his fault but also a product of the Terps' run-first offense. His route running could also use some work, but that's something NFL coaches should be able to help him with. Like most receivers entering the league, Heyward-Bey has weaknesses, but none of them is unfixable. With world-class speed and prototypical wideout size, many teams will be clamoring to draft him this April. And in the later rounds of your fantasy draft, you probably should, too, especially if he lands on a club with a strong-armed QB.

Cook is another raw talent with jaw-dropping speed but some holes in his game. He didn't become a full-time starter until last season, and even then he finished with only 37 catches and three scores. He doesn't have good blocking skills or natural instincts. He doesn't have much in terms of strength or toughness. He doesn't ... well, that's already plenty of downsides. But don't worry, there are also upsides.

In addition to his 4.50 40 - the only tight end to run a better one since '04 is the Niners' Vernon Davis - Cook had a ridiculous 41-inch vertical jump, so he can clearly sky to catch passes too high for many tight ends. And with the best broad-jump distance of anyone at his position, he has the explosiveness to beat his defender off the line. These measurable numbers probably will make Cook a first-day pick, and teams might be willing to put up with his weaknesses because of his outstanding athleticism. If, come training camp, it appears that he'll get consistent playing time, he's certainly a rookie to watch.

Finally, maybe the most intriguing player in the '09 draft is White, a quarterback while at West Virginia but a guy few scouts think can be an NFL signalcaller. His arm isn't very strong, and his play as a passer was often inconsistent. But White was unstoppable as a runner, setting the NCAA career record for most rushing yards by a QB, so he definitely offers pro teams plenty of upside.

Whether White is drafted as QB or receiver - the latter being the spot many believe he's best-suited for in the NFL - it shouldn't really matter to fantasy owners. What's important is that he is a freakish athlete who can contribute in a number of capacities. For clubs that run the "Wildcat" offense, White would be the perfect triggerman, as his top-notch speed is complemented by his experience at QB, so defenses would have to respect the pass when the ball's in his hands. If he can also develop his skills as a wideout, he would truly be a triple threat, a la the Steelers' Kordell Stewart.

If White lands in the right system, he could be an extremely effective change-of-pace QB, as the possibilities when he's behind center are numerous. Whether he's on the field enough to make a fantasy impact is another story, but owners might want to roll the dice on his potential. As a late-round pick, few investments could net you a bigger return.