Calais Campbell: Frank Gore was 49ers' biggest departure of 2015 summer

The San Francisco 49ers experienced an exodus of sorts during the summer, with their coaching staff undergoing an upheaval, four key players retiring, and a number of others departing for greener pastures.

Naturally, Arizona Cardinals defensive end Calais Campbell was thrilled about this development, and pointed to Frank Gore's singular talent as the Bay Area's greatest loss this offseason. Gore signed a three-year deal with the Indianapolis Colts in March.

"I think losing Frank Gore, that’s the biggest one," Campbell told NFL Media's Dan Hellie. "He was the heart and soul of that offense, and really that team. His passion for the game."

Gore spent the first 10 years of his career with the 49ers after being selected in the third round of the 2005 NFL Draft. The 32-year-old surpassed the 1,000-yard rushing mark in eight of his 10 campaigns with the organization, and was one of the core pieces of the franchise's revival from laughingstock to Super Bowl contender.

"He is the guy. He is really the one that we have to stop. When he got going, they were a tough team to beat," Campbell said.

Campbell appears to be relieved that he won't have to square off against Gore twice a year, and the 49ers will depend on second-year pro Carlos Hyde to spearhead the team's rushing attack in the fall.