Coach Bruce Arians, here overseeing a QB School workout this week, will have his team open training camp Friday at University of Phoenix Stadium.

Season-to-season momentum doesn't really exist in the NFL.

Too much happens between the last game a team plays and the opening of training camp for each year not to spawn something new. Players change, new injuries happen – or heal – and the variables of the opposition week-to-week make it hard to draw a direct line between the end of one year and the beginning of the next.

That doesn't mean a franchise can't build stability. That stability leads to belief, and heading into the opening Friday of training camp at University of Phoenix Stadium, the Cardinals most certainly believe in themselves.

Bruce Arians had to fight for that mindset when he first arrived in 2013 and mentioned it often that season as a mentality that evolved by midseason. Now the Cards are coming off back-to-back double-digit-win seasons and – despite Arians'

protests about avoiding the what-if game – a feeling that if quarterback Carson Palmer had stayed healthy, a much better finish than the one-and-done playoff appearance using a third-string quarterback.

Change visited the Cardinals often this offseason. Todd Bowles is no longer defensive coordinator, replaced by James Bettcher. Antonio Cromartie, Darnell Dockett and Dan Williams departed defensively. Mike Iupati was signed to upgrade the offensive line, Corey Peters and Cory Redding were added to bolster the defensive line rotation. Sean Weatherspoon was added to try and solidify a linebacking corps that still does not have Daryl Washington (and may never have him.)

Change hopefully will help the Cards even with holdovers. The team is hoping defensive backs Patrick Peterson and Tyrann Mathieu bounce back from uneven seasons after health issues. Larry Fitzgerald finally had his contract settled, a giant salary cap number no longer a shadow hanging over his future.

But what should buoy the Cardinals' hopes the most comes down to two people: Arians and Palmer. From the moment Arians walked in the door, his swagger and experience has led the players to think they could and should compete and the team's record has reflected as much.

No team is going to compete without a quarterback. That's why Palmer's return has always been the most crucial part of the Cardinals' 2015 season and its entry into training camp. Palmer has repeatedly said he is healthy, and all indications are that he is ready to have a regular camp despite tearing his ACL in November. Even with other changes, teams with a coach and good quarterback in place can win – as the Patriots have shown over the years, or the recent Packers, or the Steelers.

That's what Arians is counting on for 2015. Camp often throws curveballs – the team certainly was blind-sided when Darnell Dockett was lost for the season with a torn ACL during a camp practice last season – but it's part of the process. As long as Palmer stays upright, the Cards will be optimistic.

From there, it's about starting their own momentum from scratch over the next month.