Matthew Stafford and 5 Quarterbacks Still Making Rookie Mistakes

Some NFL quarterbacks continue to make the kind of mistakes that make you wonder what they have learned since entering the league.

Interceptions, fumbles, low passer ratings and porous completion percentages have plagued an assortment of signal-callers this season.

No one is immune, even established Pro Bowl caliber quarterbacks such as Philip Rivers have seen regression to a degree.

Others, such as Colt McCoy are young quarterbacks still developing their skills in tough environments.

Whatever the circumstances, rookie mistakes are hurting these five NFL quarterbacks.

5. Colt McCoy

Colt McCoy has made great strides in his second NFL season.

His 14 touchdown passes amidst a lackluster Cleveland Browns season and the turmoil surrounding star running back Peyton Hillis has been mildly impressive.

Where his mistakes stem from is his inability to consistently complete passes.

In five games this season, McCoy has had a completion percentage under 50, and in eight games, he has averaged under six yards per pass.

The Browns are clearly a flawed football team, and their wide receiver options leave much to be desired.

But McCoy must be able to complete passes and take vertical shots down the field to spread out the defense.

As of now, he doesn't provide the Cleveland offense with those options.

4. Matthew Stafford

Matthew Stafford has to play well down the stretch for the Detroit Lions to make the playoffs, and against the Minnesota Vikings in Week 13, he did just that.

Stafford completed 20-29 passes for 227 yards and two touchdowns. The type of performance that can lead a team to the postseason.

The problem is that in recent weeks, the Lions signal-caller has made his share of mistakes.

Stafford has 10 interceptions over the last five games.

The good news is that only one of those picks has come in the month of December.

With no help from the NFL's 23rd-ranked rushing attack, Stafford must handle the ball carefully for the Lions to continue playing games into January.

3. Mark Sanchez

Mark Sanchez is an unpredictable quarterback.

On seven different occasions this season, he has thrown for under 200 yards, and yet, in three other games, he has had over 300 yards passing.

The New York Jets need consistency under center in order to make a legitimate run at this year's Super Bowl.

Especially considering the ground-n-pound philosophy has fallen apart for the Jets.

Shonn Greene and LaDainian Tomlinson combined have under 1,000 rushing yards this season.

If Sanchez can find a balance between the pathetic and the phenomenal, they stand a better chance of competing on the highest stage.

2. Rex Grossman

Rex Grossman has thrown multiple interceptions in five different games this season.

He also has five different contests where his longest pass was under 40 yards.

Grossman seems to refuse to elevate himself to the status of a viable starting quarterback week in and week out.

Early in the season, he was playing well, with three straight games of at least 250 passing yards.

But he has only one win in his last six starts, and in none of those games, did he go without at least one interception.

The alternative in John Beck may not be any better, but that does not excuse Grossman for continuing to make rookie mistakes.

1. Philip Rivers

Through 12 games this season, Philip Rivers has completed 62.2 percent of his passes.

Last year, he completed a career high 66 percent.

This season, he already has 17 interceptions and six fumbles.

All of last year, he had only 13 interceptions and four fumbles.

The regression of Rivers this season is well documented, and whether it's due to an undisclosed injury or poor play is uncertain.

What is known is that his mistakes have hampered the San Diego Chargers ability to win football games.

Their 6-7 record verifies that.