It is always dangerous to discount underperforming players after only three weeks, but it's also important to regularly reassess your fantasy players based on what we've seen on the field.

At the QB position, Tony Romo (Cowboys) and Tom Brady (Patriots) have been so disappointing they've even been outscored by preseason third-stringer Austin Davis (Rams).

And there are valid reasons to downgrade both, as Dallas is more determined to run the ball than anticipated while New England's offensive line has crumbled. However, both have been too consistent for too many years to consider them anything worse than QB2s.

At WR and TE, fantasy points can be volatile, so it is important not to rush to judgment. But, there are legitimate reasons to downgrade Vincent Jackson (WR, Buccaneers), Larry Fitzgerald (WR, Cardinals), Torrey Smith (WR, Ravens), and Jordan Cameron (TE, Browns).

While none should be cut, if you can find a willing trade partner valuing them based on preseason hype, feel free to offload them.

Meanwhile, no position has disappointed quite like RB, where elite preseason players have let down their owners. Injuries have derailed Jamaal Charles (Chiefs), and Adrian Peterson (Vikings) is no longer playing for off-the-field reasons, but one has to dig a little deeper to understand why Matt Forte (Bears), Eddie Lacy (Packers) and LeSean McCoy (Eagles) haven't performed better.

Both Forte's and Lacy's best excuse is simply that they have faced some very talented defenses thus far. Their matchups will get easier. Meanwhile, offensive line issues and additional carries for Eagles backup Darren Sproles have minimized McCoy's impact.

However, McCoy has still averaged 23.3 touches per game, and the offensive line will get healthier in the coming weeks. Thus, while all three may not wind up dominating quite as their owners hoped, they should still be considered RB1s.

Alex Case is amNY's fantasy football columnist.