SANTA CLARA, Calif. -- When the 49ers take the field Sunday against the Giants, they could have three defensive rookies starting who began the season as backups.
That's just the way their 0-9 season has gone.
The youth movement in Kyle Shanahan's first season as coach began on offense, with rookie C.J. Beathard taking over under center from Brian Hoyer.
That theme is continuing on the other side of the ball, starting with No. 3 pick Solomon Thomas at defensive end, cornerback Ahkello Witherspoon and safety Adrian Colbert.
Along with promising linebacker Reuben Foster, who's expected to make his fourth career start, the rookie quartet will be given an opportunity to develop together as the rebuilding project unfolds in the second half.
"You can never be afraid to play a young guy. Ever," defensive coordinator Robert Saleh said. "Will you have lumps with them learning along the way? I do believe so."
Those lumps have led to the longest losing streak to begin a season in franchise history. But it's been clear since the spring that this season was going to be about building for the future, which means allowing young players to find their footing with extensive playing time.
"How can you get that young guy to play like a veteran? He has to play," Saleh said. "The more they play, the quicker as a staff we can get those guys to play like veterans while they're youthful. With all that speed and juice that they just got out of college, that's how you get those fast, explosive defenses that you've seen in this scheme."
Thomas returned to practice this week after sustaining a knee injury Oct. 29 in Philadelphia. He's taken over the starting job with veterans Tank Carradine and Arik Armstead on injured reserve. Witherspoon, a third-round pick, was made a full-time starter when Rashard Robinson was traded at the deadline to the New York Jets.
Colbert, a seventh-round pick, will be the team's third starting free safety this season. Both previous starters, Jimmie Ward and Jaquiski Tartt, are done for the season after they both fractured forearms in consecutive games.
Witherspoon appreciates the chance to grow with his fellow rookies.
"There's definitely some connection out there with them," Witherspoon said. "It's something we want to build on for now and as well as the future. We believe we can be contributors for this organization. So we just want to keep bonding with another, keep getting better with one another."
NOTES: Running back Carlos Hyde was fined by the NFL for his role in a fight that broke out against the Cardinals on Sunday that led to his ejection. Hyde took exception to a hit on Beathard as he slid during a scramble. General manager John Lynch gave Hyde a high-five on the sideline as he headed to the locker room after the altercation with Arizona lineman Frostee Rucker. "I think he was just more hyped about me sticking up for my quarterback, sticking up for my teammates," Hyde said.
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