PHILADELPHIA (973espn.com) — Zach Ertz cashed in his chips on Monday, agreeing to a monster five-year, $42.5 million extension with the Eagles.

Almost half of the contract, $20 million, is guaranteed in a deal which makes Ertz the fourth-highest paid tight end in pro football behind Seattle's Jimmy Graham, Jacksonville's Julius Thomas, and Patriots star Rob Gronkowski.

"I mean, my goal definitely isn’t to be top five; it’s to be the best in the league," Ertz said at the NovaCare Complex Monday after the deal was signed. "That’s something that I’m going to take pride in [trying] to accomplish. I don’t play this game to be an average tight end. I play this game to be the best tight end I can possibly be and win as many football games as I possibly can. And I’m going to push myself to accomplish those goals over the next five years."

(Listen to John McMullen discuss Zach Ertz's new deal)

Ertz has been very productive as a receiver since arriving in Philadelphia as a second-round pick in 2013 out of Stanford, amassing 169 catches for 2,024 yards and nine touchdowns over his three years with the Eagles. His rookie deal was set to expire after the 2016 season and he is now tied to Philadelphia through the 2021 campaign.

"First and foremost, I want to thank Howie [executive vice president of football operations Howie Roseman] and Mr. Lurie [Chairman and CEO Jeffrey Lurie]," Ertz said. "They had faith in me three years ago to bring me to Philadelphia and I am extremely thankful for that and I am extremely thankful for them allowing me to be here for six more years."

Ertz is coming off a year in which he put up career-highs in both receptions (75) and receiving yards (853) and got especially hot late in the season, setting a franchise record with 30 catches over the team's final three games, a mark which was the best over any three-game span in team lore.

During his rookie campaign, Ertz played in 41 percent of the team's snaps due to his deficiencies as a blocker. By his sophomore campaign that was up to 50 percent and last year the California native was in on 68 percent of the offensive snaps, largely due to his improvement in that phase of the game,

The highly-regarded player-rating website Pro Football Focus rated Ertz as the fourth best tight end in the NFL -- behind only Gronkowski, Tennessee's Delanie Walker, and Cincinnati's Tyler Eifert. His strong finish was due to his receiving skills obviously but also because of his vast improvement as a run blocker, where he placed sixth among his peers.

"Numbers are one thing, but I also think (former coach) Chip (Kelly) pushed me in ways that aren’t reflected in numbers," Ertz said. "I think my blocking has progressed in these three years to levels that I probably wouldn’t have reached if it weren’t for him and Coach Peelle [Eagles tight ends coach Justin Peelle]. Those guys have pushed me to be a player that I definitely wasn’t when I first came into the league, both on the field and off the field. I owe a lot of my success and a lot of my future success to Coach Kelly."

That said, there is a new sheriff in town and the ascending tight end is excited to moving into a more traditional NFL system that could better take advantage of his receiving skills.

"I’m excited to be in this system," Ertz admitted. "I talked to (new coach) Doug (Pederson) briefly today: it was primarily about Philadelphia and being back in this city. But yeah, I am extremely excited to be in his offense. I think the things that he and Coach Reid [Chiefs head coach Andy Reid] have done with tight ends in the past is something that I am really looking forward to."

Ertz could have bet on himself in the '16 campaign and likely made even more money but the 25-year-old potentially sacrificed a few dollars on the back end to make a commitment to the team that drafted him.

"I don’t play the game for financial success," Ertz claimed. "Ultimately, I’m going to play the game to be the best player that I can be. The money -- I never looked at it as something that I needed to get done this offseason.

"I’m very frugal off the field and I don’t really spend, so the money has never been something that I’ve paid attention to. I don’t really care about the money, honestly. All I care about is winning football games, and this commitment that the Eagles have placed in me is something that I take a lot of pride in."

The Eagles are not sure who will be throwing the football to Ertz next season just yet but the tight end believes impending free agent signal caller Sam Bradford wants to be back.

"I think he’s excited. He wants to be in Philadelphia," Ertz said when asked about Bradford. "Whether he’s back here or not, that’s none of my business, honestly. He’s going to do what’s best for him and the Eagles are going to do what’s best for us. But at the end of the day, I think he does want to be here."

There is no longer any need to think about Ertz, though, who now has the longest deal of any Eagles player moving forward.

"Growing up, I never would have expected to be the face of a franchise," Ertz said. "But at the same time, I think the work that I’ve put in has put me in this situation. I’m not going to be satisfied.

"Being the face of the Philadelphia [Eagles], I think it comes with a lot of responsibility. This franchise has been successful for a lot of years and I want to be successful for a lot of years. I think I’m going to put pressure on myself and my teammates to be the best players that they can be. I think everyone’s excited for the next couple of years."

-John McMullen covers the Eagles and the NFL for 973ESPN.com. You can reach him at jmcmullen44@gmail.com or on Twitter @JFMcMullen