As recently as one week ago, the start of the NFL season for the Eagles was little more than … meh.

The Birds were a middling franchise with an unexciting starting quarterback and an exciting future well to far in the future.

But then everything changed when Sam Bradford was sent to the Vikings in exchange for a first round pick — and rookie Carson Wentz, initially told he would sit out for nine months, became the Week 1 starter.

Now Eagles fans are giddy with anticipation. Here's a look at the three biggest reasons why we can't wait for kickoff between Philadelphia and Cleveland, at 1 p.m. Sunday on CBS:

1. Is Wentz ready?

He threw 24 passes in the preseason before being pulled for two broken ribs. He completed 12 and looked decent. 

But without a body of preseason work for Birds fans to judge the first-year QB out of North Dakota State on, they're left to trust Philly's coaching staff — and the man himself — that Wentz is the right man to start.

“I got some really good experience in the first preseason game," Wentz told the media Wednesday. "I definitely felt comfortable in that one. The game felt definitely slowed down for me and everything. I do feel very comfortable and going forward here Sunday is going to be exciting and I feel confident and ready.”

"I have always felt that whenever Carson got his chance, whether it was next year or Game 3 or Game 10, I’ve always felt he would be ready," offensive coordinator Frank Reich said, "or even for Game 1, I feel he'll be ready."

2. Can the defense lift the offense?

Many have surmised that the key to the Eagles success is a potent defense that gives a low-scoring offense a chance. Is that defensive coordinator Jim Schwartz' plan?

"I think we can help any quarterback by keeping the score down; we can help quarterback by giving him good field position; we can help any quarterback by giving him the ball back, whether it's on a third down stop or a red zone stop or whatever it is," Schwartz said. "I think that's the part that we are going to play. We need to worry about our own selves and we need to worry about stopping the opponent and not really worry too much about what's happening on the other side of the ball. There's always going to be things [that help the offense]: We'll score points or we might turn the ball over. Our job is to go out and get them stopped regardless of what happens."

3. Keep the Browns top weapons in check

The Browns are most analysts' pick to finish last or near last in the NFL this season and by all accounts the Eagles' top chance for a win, at the Linc with home-field advantage. But there are a few big names to worry about — and taking Cleveland lightly could leave Philly with a loss to open the campaign.

"As a defense, our job is to go stop the opponent, not to take anything else, not to carry any other flag other than going out and stopping [Robert Griffin III] and stopping [Terrelle] Pryor and Joe Thomas and [Gary] Barnidge," Schwartz said. "They have some good players on offense and we are going to have to play our very best to stop those guys and get off the field on third down, create negative plays, create turnovers."

With Wentz a big unknown, keeping the Browns' offense under wraps could be the deciding factor Sunday.