The unexpected alterations the San Francisco 49ers and Kansas City Chiefs have made since their last Super Bowl…..

When the San Francisco 49ers and the Kansas City Chiefs met in Super Bowl LIV four years ago, the rosters looked vastly different than they do now for Super Bowl LVIII.

While head coaches Kyle Shanahan of San Francisco and Andy Reid of Kansas City remain the constants, only a select group of key players have been retained from that 31-20 victory for the Chiefs, who won their first Super Bowl in 50 years.

In an age of roster volatility from one season to another, the San Francisco 49ers have managed to keep eight core players — fullback Kyle Juszczyk, receiver Deebo Samuel, tight end George Kittle, defensive end Nick Bosa, linebackers Fred Warner and Dre Greenlaw, defensive tackle Arik Armstead, and punter Mitch Wishnowski. Only the latter three players have never been invited to a Pro Bowl.

Meanwhile, the Chiefs still have the player most integral to their success, quarterback Patrick Mahomes, who’s now led them to four Super Bowl appearances in the five seasons. Mahomes will try to lead Kansas City to its third Super Bowl victory in five years and the fourth in franchise history on Feb. 11 in Las Vegas.

In addition to Mahomes, the Chiefs have kept three All-Pro performers in tight end Travis Kelce, guard Joe Thuney (out with a torn pectoral muscle), and defensive tackle Chris Jones, along with kicker Harrison Butker, receiver Mecole Hardman, tight end Blake Bell, guard Nick Allegretti.

Let’s take a look at where each teams made roster changes that have had the greatest impact on their success heading into Super Bowl LVIII.

San Francisco 49ers: Key additions since Super Bowl LIV