Updated

Stanford is back on the field and ready to face a familiar challenge.

With a blue sky and a setting sun providing a colorful California backdrop, the two-defending Pac-12 champions began the first half of its split spring practice schedule Monday. The theme has practically become an annual tradition: replacing several starters headed to the NFL and coaches who have moved on to other jobs.

"I told them the first day, 'We love playing a lot of people.' I love to say we've played as many players as anybody the last three years," Cardinal coach David Shaw said following the evening workout. "When you play a lot of guys and guys graduate, their backups have a lot of experience."

Shaw's retooling efforts will be slightly different this year.

Most of the departures are on the defensive side, including top assistant and defensive mastermind Derek Mason, who left to become Vanderbilt's head coach. Among the other notable losses: linebackers Trent Murphy and Shayne Skov, defensive end Ben Gardner, running back Tyler Gaffney, left guard David Yankey, right tackle Cameron Fleming and free safety Ed Reynolds.

Replacing key contributors is nothing new on The Farm.

In the past few seasons, Stanford has seamlessly overcome the losses of Jim Harbaugh, Toby Gerhart, Andrew Luck, Coby Fleener, Zach Ertz and Stepfan Taylor, to name a few. Several assistant coaches and support staff also have moved elsewhere.

"It's a testament to the recruiting," said quarterback Kevin Hogan, who will be entering his redshirt junior season in the fall. "And I feel like when we replace guys, they are guys that have already been in this system for at least a year or two."

Most of the questions this spring, unlike the last two years, are about the defense.

Murphy, Skov and Gardner not only carried the defensive load, they were team leaders. Reynolds also earned first-team Pac-12 honors the past two seasons anchoring the back-end of one of the nation's best defenses.

Despite the losses, Stanford's defense could be stout again — just not in the way most have become accustomed. Instead of the front seven leading the way, the secondary should be a strength with the return of starting cornerbacks Alex Carter and Wayne Lyons — both already among the Pac-12's best — and strong safety Jordan Richards.

On the offensive side, the depth at quarterback might be the best Stanford has had during its recent renaissance.

Hogan has led the program to consecutive Rose Bowls. Highly touted recruit Ryan Burns, who redshirted as a freshman, could provide some competition and Keller Chryst — one of the country's top pocket-passers coming out of high school — will join the mix in the fall.

Burns will not participate in the first part of spring practice because of a "disciplinary issue," Shaw said. He declined to elaborate.

The quarterback room is so crowded that Dallas Lloyd, the only signal-caller other than Hogan to see meaningful snaps last season, is moving to defense along with wide receiver Kodi Whitfield. Both are among those competing to replace Reynolds at free safety.

"It's really just a good opportunity," Whitfield said, crediting Richards and other upperclassmen for helping him transition. "Every time that an old guy steps out, you've got a guy that's young and he's played before and he's that veteran on that team."

Even with the loss of four starters, the offensive line has plenty of experience and Shaw said it could be the "most athletic offensive line since we've been here." And while 1,700-yard rusher Gaffney is gone, Stanford has shown an ability to replace running backs in recent seasons, including Gerhart and Taylor.

The other position to watch is tight end, which all but disappeared last season after Ertz and Levine Toilolo left for the NFL. Shaw is hoping Austin Hooper, Eric Cotton and Greg Taboada can improve by the fall, when sought-after freshman Dalton Schultz also arrives.

Wide receiver, which began last season with major question marks, might have the least amount of questions this spring.

The only real issue is getting wide receiver and All-American kick returner Ty Montgomery healthy again after he injured his knee in the Rose Bowl. He's sitting out the first portion of spring practice, as previously announced. He will wear a brace around his knee when he returns but is expected to shed the brace by the time the season starts, Shaw said.

Defensive tackle David Parry is the only other returning Stanford starter who is not participating in practice. Shaw said Parry is still dealing with an injury to his midsection.

___

Antonio Gonzalez can be reached at: www.twitter.com/agonzalezAP