By Denny Basens, Sports Talk Philly staff writer 
The Philadelphia Eagles have been struggling over the last two weeks. The team's two-game losing streak has raised a number of questions about the club's ability to compete with a difficult stretch of the schedule on the horizon.
In addition to failing to maintain their discipline by committing 27 penalties, the team has had a number of key players underachieve.
Here's a look at some of the biggest underachievers in the early part of the season that need to step their games up in the coming weeks.
Connor Barwin
Barwin has been logging a heavy workload of snaps as one of the team's starting defensive ends, but has not made the most of them.
Through six games, Barwin has just one sack, which came on opening day against the hapless Cleveland Browns. The 30-year old has gone silent ever since.
A former linebacker in Billy Davis' 3-4 scheme, Barwin is showing that he may not be a fit in Schwartz's system. It's not just that he's been unable to generate pressure on the quarterback, he also hasn't been helpful in run defense.
Barwin's best attributes are that he's a smart, instinctive player, and is versatile enough to do a variety of things, but those skills go to waste as a defensive end constantly locked in battle with opposing tackles.
Zach Ertz
It may be a little unfair to throw a lot of criticism Ertz's way.
He is only two games removed from his rib injury that held him out of action for three weeks, but he's been underwhelming as well.
Ertz is being paid like a dominant tight end, and hasn't performed that way at all. The fourth-year pro dropped what should have been a touchdown in the fourth of quarter of last Sunday's loss to the Redskins, as the ball sailed right through his hands.
In an offense starving for a consistent playmaker in the aerial attack, Ertz was being counted on to step up and he hasn't done it yet.
Vinny Curry
This was supposed to be the season where Vinny Curry would finally be unleashed.
After signing a contract that pays him starter's money, Curry has been just a rotational player through six games. Like Barwin, Curry has just one sack through six games.
While Curry has been battling an injury he suffered in the preseason, the simple fact is that he hasn't been giving the team much pop off of the bench.
Jason Kelce
The starting center hasn't played well since 2014.
Kelce continues to underperform at the center position. The costly, drive-killing penalties are piling up. He isn't generating much push in the run game, and is struggling in pass protection.
Making calls at the line is Kelce's specialty, but there comes a point where that's not good enough. The Eagles need better play from their center, and if a dramatic turnaround doesn't soon occur, it may be time to consider other options.
