LOS ANGELES -- Wade Phillips has spent more years in the NFL than Sean McVay has spent on this planet. Phillips began as a defensive line coach for the Houston Oilers in 1976, 10 years before McVay was even born. And now he is 69, nearly 40 years older than McVay, his new boss, who won't turn 31 until Jan. 24.

They arrive in Los Angeles as an ideal pairing.

The Rams sent shock waves through the industry on Thursday by taking a leap of faith and entrusting McVay to be the head coach for one of the most crucial times in their franchise's history. But part of their comfort seemingly stemmed from their ability to surround McVay with experienced coaches. And a key step in that process was hiring Phillips, who is expected to come in as the defensive coordinator but also as a mentor.

Phillips has spent 25 years as a defensive coordinator and nine others as a full-time head coach. The Rams will be his 10th NFL team. His last was the Denver Broncos, an organization that employed him on two separate occasions.

Most recently, Phillips spent two years presiding over the game's greatest current defense.

In 2015, the Broncos allowed the fewest rushing yards per carry and the fewest passing yards per game, then rode that defense to a Super Bowl title. In 2016, they ranked first in DVOA (defense-adjusted value over average) for the second straight year, then Gary Kubiak stepped down as head coach. The Broncos replaced him with the defensive-minded Vance Joseph, and Phillips ultimately moved west.

He'll bring with him a defense that traditionally runs a 3-4 scheme and uses a lot of man-to-man coverage, and there will be questions about how he will make it work with the Rams.

Will Robert Quinn, a veteran defensive end, be forced to move away from his three-point stance and adjust to a role similar to the one outside linebacker DeMarcus Ware filled in Denver?

Can Phillips get away with so much man coverage with a Rams secondary that is currently thin?

Will the Rams have to beef up their linebacker depth, which mainly consists of two converted safeties in Alec Ogletree and Mark Barron?

Phillips has been around long enough to know how to adjust scheme to personnel, in much of the same way former defensive coordinator Gregg Williams did over these past three years. The Rams have talent throughout their defense, starting with standout defensive tackle Aaron Donald. But they need to try to bring back Trumaine Johnson, their No. 1 cornerback, and T.J. McDonald, their starting strong safety. And they need to round out their depth.

ESPN's Jeff Legwold contributed to this report.