POSTED: Wednesday, October 15, 2014, 3:01 AM

ZACH ERTZ always has aimed high. He doesn't want to be only a good NFL tight end; he wants to be a great one.

He wants to catch 80 passes a year. He wants to go to Pro Bowls. He wants to be mentioned in the same breath with the best tight ends in the game.

He believes he has that kind of talent. His coaches believe he has that kind of talent.

If you saw his incredible, diving touchdown catch in the first quarter Sunday night against Giants cornerback Dominique Rodgers-Cromartie, you know he has that kind of talent.

What is holding Ertz back right now is the same thing that holds back a lot of young tight ends: his blocking ability.

In the Eagles' first four games, Ertz played 64.5 percent of the offensive snaps. In the last two against the Rams and Giants, only 40.9 percent.

In the Eagles' Week 5 win over the Rams, Ertz played only 31 of 76 snaps. He was used almost exclusively as the lone tight end in three-wide receiver sets in that game. Not coincidentally, only 10 of the Eagles' 33 rushing attempts against the Rams came out of three-wide sets.

Sunday night, Ertz played only 30 of 73 snaps. While he was used in both three-wide-receiver and two-tight-end sets, it was mainly on third down or in obvious passing situations.

He was targeted five times against the Giants and had three receptions for 47 yards and a touchdown.

As a rookie last year, Ertz had 36 catches for 469 yards and four touchdowns. Through six games this season, he has 19 catches for 306 yards and two touchdowns.

His 16.1 yards-per-catch average is the best in the league among tight ends. But the breakout season he hoped for, and many others expected, is slow in developing.

"I thought I could have a big game tonight," Ertz said after the Eagles' 27-0 win over the Giants. "But it's not what the doctor ordered. We got the win. We were running the ball well the whole game. That's not my strength right now. But in the end, hopefully it will be. And I'm going to keep working hard at that."

It frequently is forgotten that Chip Kelly's offense, first and foremost, is a running offense. The Eagles ran the ball 47 percent of the time last season, which was the sixth most in the league. The Eagles led the league in rushing and LeSean McCoy ran away with the league rushing title.

"It starts with the running game," Ertz said. "LeSean is the focal point of this offense. When we get him going, everything else opens up. Everyone plays more calmly and we're able to make plays in the passing game, as well."

McCoy got off to a poor start this season. He averaged 2.7 yards per carry in the first four games. Was averaging only 1.6 out of two-tight-end sets.

Ertz was just a part of the problem with the run game. A much bigger part was the three missing starters up front. But when your offensive line is struggling, other shortcomings become magnified.

Reducing Ertz' snaps wasn't an easy thing to do, given his ability as a pass-catcher. But Kelly thought it was critical to do whatever it took to get McCoy going.

So, in the Rams game, Kelly gave the No. 3 tight end, James Casey, extended playing time (a season-high 25 snaps), teaming him with Brent Celek, who is one of the league's best blocking tight ends, in two-tight-end sets and using Ertz in "11'' personnel formations (three wide receivers).

The strategy was effective. McCoy rushed for 81 yards on 24 carries in the win. Sixty-one of those 81 yards came in the two-tight-sets with Celek and Casey.

With Celek playing 57 of 73 snaps Sunday night against the Giants, McCoy had his best game of the season, rushing for 149 yards on 22 carries.

"The running game was the key [against the Giants]," Ertz said. "Like we've said all year, we've got to get the running game going. And [Sunday], we did that.

"Brent did an unbelievable job blocking all night. He's probably the best run-blocking tight end in the league."

Ertz also had a couple of nice blocks to help McCoy. He had a pretty good wham block on Giants defensive end Jason Pierre-Paul to help spring him for an 18-yard gain on the Eagles' first possession. And he had another good block on safety Quintin Demps on a McCoy 15-yard run in the second quarter. Both runs came out of two-tight end sets.

All three of Ertz's receptions came on the Eagles' first two possessions, both scoring drives. He had a 9-yard catch on a game-opening, 10-play drive that resulted in the first of Cody Parkey's two field goals. And he had two more catches on the Eagles' next possession - a 23-yarder on a short cross on third-and-8, and then the brilliant, 15-yard touchdown catch from Nick Foles on third-and-6.

"I was having fun," Ertz said. "That's all I wanted to do. Go out there and enjoy the moment. You're playing on prime-time football. It was nice to take a big, deep breath after that first catch and settle down and have another big long one, and then the corner route [for the touchdown]. It was just good to go out there and make plays for the team."

While he still might be developing as an NFL blocker, Ertz already is making his mark as a receiver. He is second on the Eagles to Jeremy Maclin in first-down receptions (16) and has become Foles' go-to guy on third down.

He leads the team in third-down receptions (10), as well as third-down receptions for first downs (10). The only tight end in the league with more third-down catches than Ertz is the Chargers' Antonio Gates, an eight-time Pro Bowler, who has 11.

"That's what my role has been so far this year," Ertz said. "Obviously, I want to play all three downs. But third down has been the down where I am able to go in and know consistently I'm going to be able to make plays for the team.

"Nick trusts me. Even on the scrambling drill you saw at the end [of the third quarter], it was a 40-yard pass. But it was just inches away from being a big play. So Nick trusts me, and we've got to keep that going."